<?php  // $Id$

require_once($CFG->libdir.'/filelib.php');

/// CONSTANTS ///////////////////////////////////////////////////////////

define('FORUM_MODE_FLATOLDEST', 1);
define('FORUM_MODE_FLATNEWEST', -1);
define('FORUM_MODE_THREADED', 2);
define('FORUM_MODE_NESTED', 3);

define('FORUM_FORCESUBSCRIBE', 1);
define('FORUM_INITIALSUBSCRIBE', 2);
define('FORUM_DISALLOWSUBSCRIBE',3);

define('FORUM_TRACKING_OFF', 0);
define('FORUM_TRACKING_OPTIONAL', 1);
define('FORUM_TRACKING_ON', 2);

define('FORUM_UNSET_POST_RATING', -999);

define ('FORUM_AGGREGATE_NONE', 0); //no ratings
define ('FORUM_AGGREGATE_AVG', 1);
define ('FORUM_AGGREGATE_COUNT', 2);
define ('FORUM_AGGREGATE_MAX', 3);
define ('FORUM_AGGREGATE_MIN', 4);
define ('FORUM_AGGREGATE_SUM', 5);

/// STANDARD FUNCTIONS ///////////////////////////////////////////////////////////

/**
 * Given an object containing all the necessary data,
 * (defined by the form in mod.html) this function
 * will create a new instance and return the id number
 * of the new instance.
 * @param object $forum add forum instance (with magic quotes)
 * @return int intance id
 */
function forum_add_instance($forum) {
	global $CFG;

	$forum->timemodified = time();

	if (empty($forum->assessed)) {
		$forum->assessed = 0;
	}

	if (empty($forum->ratingtime) or empty($forum->assessed)) {
		$forum->assesstimestart  = 0;
		$forum->assesstimefinish = 0;
	}

	if (!$forum->id = insert_record('forum', $forum)) {
		return false;
	}

	if ($forum->type == 'single') {  // Create related discussion.
		$discussion = new object();
		$discussion->course   = $forum->course;
		$discussion->forum	= $forum->id;
		$discussion->name	 = $forum->name;
		$discussion->intro	= $forum->intro;
		$discussion->assessed = $forum->assessed;
		$discussion->format   = $forum->type;
		$discussion->mailnow  = false;
		$discussion->groupid  = -1;

		if (! forum_add_discussion($discussion, $discussion->intro)) {
			error('Could not add the discussion for this forum');
		}
	}

	if ($forum->forcesubscribe == FORUM_INITIALSUBSCRIBE) {
	/// all users should be subscribed initially
	/// Note: forum_get_potential_subscribers should take the forum context,
	/// but that does not exist yet, becuase the forum is only half build at this
	/// stage. However, because the forum is brand new, we know that there are
	/// no role assignments or overrides in the forum context, so using the
	/// course context gives the same list of users.
		$users = forum_get_potential_subscribers(get_context_instance(CONTEXT_COURSE, $forum->course), 0, 'u.id, u.email', '');
		foreach ($users as $user) {
			forum_subscribe($user->id, $forum->id);
		}
	}

	$forum = stripslashes_recursive($forum);
	forum_grade_item_update($forum);

	return $forum->id;
}


/**
 * Given an object containing all the necessary data,
 * (defined by the form in mod.html) this function
 * will update an existing instance with new data.
 * @param object $forum forum instance (with magic quotes)
 * @return bool success
 */
function forum_update_instance($forum) {
	$forum->timemodified = time();
	$forum->id		   = $forum->instance;

	if (empty($forum->assessed)) {
		$forum->assessed = 0;
	}

	if (empty($forum->ratingtime) or empty($forum->assessed)) {
		$forum->assesstimestart  = 0;
		$forum->assesstimefinish = 0;
	}

	$oldforum = get_record('forum', 'id', $forum->id);

	// MDL-3942 - if the aggregation type or scale (i.e. max grade) changes then recalculate the grades for the entire forum
	// if  scale changes - do we need to recheck the ratings, if ratings higher than scale how do we want to respond?
	// for count and sum aggregation types the grade we check to make sure they do not exceed the scale (i.e. max score) when calculating the grade
	if (($oldforum->assessed<>$forum->assessed) or ($oldforum->scale<>$forum->scale)) {
		forum_update_grades($forum); // recalculate grades for the forum
	}

	if ($forum->type == 'single') {  // Update related discussion and post.
		if (! $discussion = get_record('forum_discussions', 'forum', $forum->id)) {
			if ($discussions = get_records('forum_discussions', 'forum', $forum->id, 'timemodified ASC')) {
				notify('Warning! There is more than one discussion in this forum - using the most recent');
				$discussion = array_pop($discussions);
			} else {
				// try to recover by creating initial discussion - MDL-16262
				$discussion = new object();
				$discussion->course   = $forum->course;
				$discussion->forum	= $forum->id;
				$discussion->name	 = $forum->name;
				$discussion->intro	= $forum->intro;
				$discussion->assessed = $forum->assessed;
				$discussion->format   = $forum->type;
				$discussion->mailnow  = false;
				$discussion->groupid  = -1;

				forum_add_discussion($discussion, $discussion->intro);

				if (! $discussion = get_record('forum_discussions', 'forum', $forum->id)) {
					error('Could not add the discussion for this forum');
				}

			}
		}
		if (! $post = get_record('forum_posts', 'id', $discussion->firstpost)) {
			error('Could not find the first post in this forum discussion');
		}

		$post->subject  = $forum->name;
		$post->message  = $forum->intro;
		$post->modified = $forum->timemodified;

		if (! update_record('forum_posts', ($post))) {
			error('Could not update the first post');
		}

		$discussion->name = $forum->name;

		if (! update_record('forum_discussions', ($discussion))) {
			error('Could not update the discussion');
		}
	}

	if (!update_record('forum', $forum)) {
		error('Can not update forum');
	}

	$forum = stripslashes_recursive($forum);
	forum_grade_item_update($forum);

	return true;
}


/**
 * Given an ID of an instance of this module,
 * this function will permanently delete the instance
 * and any data that depends on it.
 * @param int forum instance id
 * @return bool success
 */
function forum_delete_instance($id) {

	if (!$forum = get_record('forum', 'id', $id)) {
		return false;
	}

	$result = true;

	if ($discussions = get_records('forum_discussions', 'forum', $forum->id)) {
		foreach ($discussions as $discussion) {
			if (!forum_delete_discussion($discussion, true)) {
				$result = false;
			}
		}
	}

	if (!delete_records('forum_subscriptions', 'forum', $forum->id)) {
		$result = false;
	}

	forum_tp_delete_read_records(-1, -1, -1, $forum->id);

	if (!delete_records('forum', 'id', $forum->id)) {
		$result = false;
	}

	forum_grade_item_delete($forum);

	return $result;
}


/**
 * Function to be run periodically according to the moodle cron
 * Finds all posts that have yet to be mailed out, and mails them
 * out to all subscribers
 * @return void
 */
function forum_cron() {
	global $CFG, $USER;

	$cronuser = clone($USER);
	$site = get_site();

	// all users that are subscribed to any post that needs sending
	$users = array();

	// status arrays
	$mailcount  = array();
	$errorcount = array();

	// caches
	$discussions	 = array();
	$forums		  = array();
	$courses		 = array();
	$coursemodules   = array();
	$subscribedusers = array();


	// Posts older than 2 days will not be mailed.  This is to avoid the problem where
	// cron has not been running for a long time, and then suddenly people are flooded
	// with mail from the past few weeks or months
	$timenow   = time();
	$endtime   = $timenow - $CFG->maxeditingtime;
	$starttime = $endtime - 48 * 3600;   // Two days earlier

	if ($posts = forum_get_unmailed_posts($starttime, $endtime, $timenow)) {
		// Mark them all now as being mailed.  It's unlikely but possible there
		// might be an error later so that a post is NOT actually mailed out,
		// but since mail isn't crucial, we can accept this risk.  Doing it now
		// prevents the risk of duplicated mails, which is a worse problem.

		if (!forum_mark_old_posts_as_mailed($endtime)) {
			mtrace('Errors occurred while trying to mark some posts as being mailed.');
			return false;  // Don't continue trying to mail them, in case we are in a cron loop
		}

		// checking post validity, and adding users to loop through later
		foreach ($posts as $pid => $post) {

			$discussionid = $post->discussion;
			if (!isset($discussions[$discussionid])) {
				if ($discussion = get_record('forum_discussions', 'id', $post->discussion)) {
					$discussions[$discussionid] = $discussion;
				} else {
					mtrace('Could not find discussion '.$discussionid);
					unset($posts[$pid]);
					continue;
				}
			}
			$forumid = $discussions[$discussionid]->forum;
			if (!isset($forums[$forumid])) {
				if ($forum = get_record('forum', 'id', $forumid)) {
					$forums[$forumid] = $forum;
				} else {
					mtrace('Could not find forum '.$forumid);
					unset($posts[$pid]);
					continue;
				}
			}
			$courseid = $forums[$forumid]->course;
			if (!isset($courses[$courseid])) {
				if ($course = get_record('course', 'id', $courseid)) {
					$courses[$courseid] = $course;
				} else {
					mtrace('Could not find course '.$courseid);
					unset($posts[$pid]);
					continue;
				}
			}
			if (!isset($coursemodules[$forumid])) {
				if ($cm = get_coursemodule_from_instance('forum', $forumid, $courseid)) {
					$coursemodules[$forumid] = $cm;
				} else {
					mtrace('Could not course module for forum '.$forumid);
					unset($posts[$pid]);
					continue;
				}
			}


			// caching subscribed users of each forum
			if (!isset($subscribedusers[$forumid])) {
				$modcontext = get_context_instance(CONTEXT_MODULE, $coursemodules[$forumid]->id);
				if ($subusers = forum_subscribed_users($courses[$courseid], $forums[$forumid], 0, $modcontext)) {
					foreach ($subusers as $postuser) {
						// do not try to mail users with stopped email
						if ($postuser->emailstop) {
							if (!empty($CFG->forum_logblocked)) {
								add_to_log(SITEID, 'forum', 'mail blocked', '', '', 0, $postuser->id);
							}
							continue;
						}
						// this user is subscribed to this forum
						$subscribedusers[$forumid][$postuser->id] = $postuser->id;
						// this user is a user we have to process later
						$users[$postuser->id] = $postuser;
					}
					unset($subusers); // release memory
				}
			}

			$mailcount[$pid] = 0;
			$errorcount[$pid] = 0;
		}
	}

	if ($users && $posts) {

		$urlinfo = parse_url($CFG->wwwroot);
		$hostname = $urlinfo['host'];

		foreach ($users as $userto) {

			@set_time_limit(120); // terminate if processing of any account takes longer than 2 minutes

			// set this so that the capabilities are cached, and environment matches receiving user
			$USER = $userto;

			mtrace('Processing user '.$userto->id);

			// init caches
			$userto->viewfullnames = array();
			$userto->canpost	   = array();
			$userto->markposts	 = array();
			$userto->enrolledin	= array();

			// reset the caches
			foreach ($coursemodules as $forumid=>$unused) {
				$coursemodules[$forumid]->cache	   = new object();
				$coursemodules[$forumid]->cache->caps = array();
				unset($coursemodules[$forumid]->uservisible);
			}

			foreach ($posts as $pid => $post) {

				// Set up the environment for the post, discussion, forum, course
				$discussion = $discussions[$post->discussion];
				$forum	  = $forums[$discussion->forum];
				$course	 = $courses[$forum->course];
				$cm		 =& $coursemodules[$forum->id];

				// Do some checks  to see if we can bail out now
				if (!isset($subscribedusers[$forum->id][$userto->id])) {
					continue; // user does not subscribe to this forum
				}

				// Verify user is enrollend in course - if not do not send any email
				if (!isset($userto->enrolledin[$course->id])) {
					$userto->enrolledin[$course->id] = has_capability('moodle/course:view', get_context_instance(CONTEXT_COURSE, $course->id));
				}
				if (!$userto->enrolledin[$course->id]) {
					// oops - this user should not receive anything from this course
					continue;
				}

				// Get info about the sending user
				if (array_key_exists($post->userid, $users)) { // we might know him/her already
					$userfrom = $users[$post->userid];
				} else if ($userfrom = get_record('user', 'id', $post->userid)) {
					$users[$userfrom->id] = $userfrom; // fetch only once, we can add it to user list, it will be skipped anyway
				} else {
					mtrace('Could not find user '.$post->userid);
					continue;
				}

				// setup global $COURSE properly - needed for roles and languages
				course_setup($course);   // More environment

				// Fill caches
				if (!isset($userto->viewfullnames[$forum->id])) {
					$modcontext = get_context_instance(CONTEXT_MODULE, $cm->id);
					$userto->viewfullnames[$forum->id] = has_capability('moodle/site:viewfullnames', $modcontext);
				}
				if (!isset($userto->canpost[$discussion->id])) {
					$modcontext = get_context_instance(CONTEXT_MODULE, $cm->id);
					$userto->canpost[$discussion->id] = forum_user_can_post($forum, $discussion, $userto, $cm, $course, $modcontext);
				}
				if (!isset($userfrom->groups[$forum->id])) {
					if (!isset($userfrom->groups)) {
						$userfrom->groups = array();
						$users[$userfrom->id]->groups = array();
					}
					$userfrom->groups[$forum->id] = groups_get_all_groups($course->id, $userfrom->id, $cm->groupingid);
					$users[$userfrom->id]->groups[$forum->id] = $userfrom->groups[$forum->id];
				}

				// Make sure groups allow this user to see this email
				if ($discussion->groupid > 0 and $groupmode = groups_get_activity_groupmode($cm, $course)) {   // Groups are being used
					if (!groups_group_exists($discussion->groupid)) { // Can't find group
						continue;						   // Be safe and don't send it to anyone
					}

					if (!groups_is_member($discussion->groupid) and !has_capability('moodle/site:accessallgroups', $modcontext)) {
						// do not send posts from other groups when in SEPARATEGROUPS or VISIBLEGROUPS
						continue;
					}
				}

				// Make sure we're allowed to see it...
				if (!forum_user_can_see_post($forum, $discussion, $post, NULL, $cm)) {
					mtrace('user '.$userto->id. ' can not see '.$post->id);
					continue;
				}

				// OK so we need to send the email.

				// Does the user want this post in a digest?  If so postpone it for now.
				if ($userto->maildigest > 0) {
					// This user wants the mails to be in digest form
					$queue = new object();
					$queue->userid	   = $userto->id;
					$queue->discussionid = $discussion->id;
					$queue->postid	   = $post->id;
					$queue->timemodified = $post->created;
					if (!insert_record('forum_queue', $queue)) {
						mtrace("Error: mod/forum/cron.php: Could not queue for digest mail for id $post->id to user $userto->id ($userto->email) .. not trying again.");
					}
					continue;
				}


				// Prepare to actually send the post now, and build up the content

				$cleanforumname = str_replace('"', "'", strip_tags(format_string($forum->name)));

				$userfrom->customheaders = array (  // Headers to make emails easier to track
						   'Precedence: Bulk',
						   'List-Id: "'.$cleanforumname.'" <moodleforum'.$forum->id.'@'.$hostname.'>',
						   'List-Help: '.$CFG->wwwroot.'/mod/forum/view.php?f='.$forum->id,
						   'Message-ID: <moodlepost'.$post->id.'@'.$hostname.'>',
						   'In-Reply-To: <moodlepost'.$post->parent.'@'.$hostname.'>',
						   'References: <moodlepost'.$post->parent.'@'.$hostname.'>',
						   'X-Course-Id: '.$course->id,
						   'X-Course-Name: '.format_string($course->fullname, true)
				);


				$postsubject = "$course->shortname: ".format_string($post->subject,true);
				$posttext = forum_make_mail_text($course, $forum, $discussion, $post, $userfrom, $userto);
				$posthtml = forum_make_mail_html($course, $forum, $discussion, $post, $userfrom, $userto);

				// Send the post now!

				mtrace('Sending ', '');

				if (!$mailresult = email_to_user($userto, $userfrom, $postsubject, $posttext,
												 $posthtml, '', '', $CFG->forum_replytouser)) {
					mtrace("Error: mod/forum/cron.php: Could not send out mail for id $post->id to user $userto->id".
						 " ($userto->email) .. not trying again.");
					add_to_log($course->id, 'forum', 'mail error', "discuss.php?d=$discussion->id#p$post->id",
							   substr(format_string($post->subject,true),0,30), $cm->id, $userto->id);
					$errorcount[$post->id]++;
				} else if ($mailresult === 'emailstop') {
					// should not be reached anymore - see check above
				} else {
					$mailcount[$post->id]++;

				// Mark post as read if forum_usermarksread is set off
					if (!$CFG->forum_usermarksread) {
						$userto->markposts[$post->id] = $post->id;
					}
				}

				mtrace('post '.$post->id. ': '.$post->subject);
			}

			// mark processed posts as read
			forum_tp_mark_posts_read($userto, $userto->markposts);
		}
	}

	if ($posts) {
		foreach ($posts as $post) {
			mtrace($mailcount[$post->id]." users were sent post $post->id, '$post->subject'");
			if ($errorcount[$post->id]) {
				set_field("forum_posts", "mailed", "2", "id", "$post->id");
			}
		}
	}

	// release some memory
	unset($subscribedusers);
	unset($mailcount);
	unset($errorcount);

	$USER = clone($cronuser);
	course_setup(SITEID);

	$sitetimezone = $CFG->timezone;

	// Now see if there are any digest mails waiting to be sent, and if we should send them

	mtrace('Starting digest processing...');

	@set_time_limit(300); // terminate if not able to fetch all digests in 5 minutes

	if (!isset($CFG->digestmailtimelast)) {	// To catch the first time
		set_config('digestmailtimelast', 0);
	}

	$timenow = time();
	$digesttime = usergetmidnight($timenow, $sitetimezone) + ($CFG->digestmailtime * 3600);

	// Delete any really old ones (normally there shouldn't be any)
	$weekago = $timenow - (7 * 24 * 3600);
	delete_records_select('forum_queue', "timemodified < $weekago");
	mtrace ('Cleaned old digest records');

	if ($CFG->digestmailtimelast < $digesttime and $timenow > $digesttime) {

		mtrace('Sending forum digests: '.userdate($timenow, '', $sitetimezone));

		$digestposts_rs = get_recordset_select('forum_queue', "timemodified < $digesttime");

		if (!rs_EOF($digestposts_rs)) {

			// We have work to do
			$usermailcount = 0;

			//caches - reuse the those filled before too
			$discussionposts = array();
			$userdiscussions = array();

			while ($digestpost = rs_fetch_next_record($digestposts_rs)) {
				if (!isset($users[$digestpost->userid])) {
					if ($user = get_record('user', 'id', $digestpost->userid)) {
						$users[$digestpost->userid] = $user;
					} else {
						continue;
					}
				}
				$postuser = $users[$digestpost->userid];
				if ($postuser->emailstop) {
					if (!empty($CFG->forum_logblocked)) {
						add_to_log(SITEID, 'forum', 'mail blocked', '', '', 0, $postuser->id);
					}
					continue;
				}

				if (!isset($posts[$digestpost->postid])) {
					if ($post = get_record('forum_posts', 'id', $digestpost->postid)) {
						$posts[$digestpost->postid] = $post;
					} else {
						continue;
					}
				}
				$discussionid = $digestpost->discussionid;
				if (!isset($discussions[$discussionid])) {
					if ($discussion = get_record('forum_discussions', 'id', $discussionid)) {
						$discussions[$discussionid] = $discussion;
					} else {
						continue;
					}
				}
				$forumid = $discussions[$discussionid]->forum;
				if (!isset($forums[$forumid])) {
					if ($forum = get_record('forum', 'id', $forumid)) {
						$forums[$forumid] = $forum;
					} else {
						continue;
					}
				}

				$courseid = $forums[$forumid]->course;
				if (!isset($courses[$courseid])) {
					if ($course = get_record('course', 'id', $courseid)) {
						$courses[$courseid] = $course;
					} else {
						continue;
					}
				}

				if (!isset($coursemodules[$forumid])) {
					if ($cm = get_coursemodule_from_instance('forum', $forumid, $courseid)) {
						$coursemodules[$forumid] = $cm;
					} else {
						continue;
					}
				}
				$userdiscussions[$digestpost->userid][$digestpost->discussionid] = $digestpost->discussionid;
				$discussionposts[$digestpost->discussionid][$digestpost->postid] = $digestpost->postid;
			}
			rs_close($digestposts_rs); /// Finished iteration, let's close the resultset

			// Data collected, start sending out emails to each user
			foreach ($userdiscussions as $userid => $thesediscussions) {

				@set_time_limit(120); // terminate if processing of any account takes longer than 2 minutes

				$USER = $cronuser;
				course_setup(SITEID); // reset cron user language, theme and timezone settings

				mtrace(get_string('processingdigest', 'forum', $userid), '... ');

				// First of all delete all the queue entries for this user
				delete_records_select('forum_queue', "userid = $userid AND timemodified < $digesttime");
				$userto = $users[$userid];

				// Override the language and timezone of the "current" user, so that
				// mail is customised for the receiver.
				$USER = $userto;
				course_setup(SITEID);

				// init caches
				$userto->viewfullnames = array();
				$userto->canpost	   = array();
				$userto->markposts	 = array();

				$postsubject = get_string('digestmailsubject', 'forum', format_string($site->shortname, true));

				$headerdata = new object();
				$headerdata->sitename = format_string($site->fullname, true);
				$headerdata->userprefs = $CFG->wwwroot.'/user/edit.php?id='.$userid.'&amp;course='.$site->id;

				$posttext = get_string('digestmailheader', 'forum', $headerdata)."\n\n";
				$headerdata->userprefs = '<a target="_blank" href="'.$headerdata->userprefs.'">'.get_string('digestmailprefs', 'forum').'</a>';

				$posthtml = "<head>";
				foreach ($CFG->stylesheets as $stylesheet) {
					$posthtml .= '<link rel="stylesheet" type="text/css" href="'.$stylesheet.'" />'."\n";
				}
				$posthtml .= "</head>\n<body id=\"email\">\n";
				$posthtml .= '<p>'.get_string('digestmailheader', 'forum', $headerdata).'</p><br /><hr size="1" noshade="noshade" />';

				foreach ($thesediscussions as $discussionid) {

					@set_time_limit(120);   // to be reset for each post

					$discussion = $discussions[$discussionid];
					$forum	  = $forums[$discussion->forum];
					$course	 = $courses[$forum->course];
					$cm		 = $coursemodules[$forum->id];

					//override language
					course_setup($course);

					// Fill caches
					if (!isset($userto->viewfullnames[$forum->id])) {
						$modcontext = get_context_instance(CONTEXT_MODULE, $cm->id);
						$userto->viewfullnames[$forum->id] = has_capability('moodle/site:viewfullnames', $modcontext);
					}
					if (!isset($userto->canpost[$discussion->id])) {
						$modcontext = get_context_instance(CONTEXT_MODULE, $cm->id);
						$userto->canpost[$discussion->id] = forum_user_can_post($forum, $discussion, $userto, $cm, $course, $modcontext);
					}

					$strforums	  = get_string('forums', 'forum');
					$canunsubscribe = ! forum_is_forcesubscribed($forum);
					$canreply	   = $userto->canpost[$discussion->id];

					$posttext .= "\n \n";
					$posttext .= '=====================================================================';
					$posttext .= "\n \n";
					$posttext .= "$course->shortname -> $strforums -> ".format_string($forum->name,true);
					if ($discussion->name != $forum->name) {
						$posttext  .= " -> ".format_string($discussion->name,true);
					}
					$posttext .= "\n";

					$posthtml .= "<p><font face=\"sans-serif\">".
					"<a target=\"_blank\" href=\"$CFG->wwwroot/course/view.php?id=$course->id\">$course->shortname</a> -> ".
					"<a target=\"_blank\" href=\"$CFG->wwwroot/mod/forum/index.php?id=$course->id\">$strforums</a> -> ".
					"<a target=\"_blank\" href=\"$CFG->wwwroot/mod/forum/view.php?f=$forum->id\">".format_string($forum->name,true)."</a>";
					if ($discussion->name == $forum->name) {
						$posthtml .= "</font></p>";
					} else {
						$posthtml .= " -> <a target=\"_blank\" href=\"$CFG->wwwroot/mod/forum/discuss.php?d=$discussion->id\">".format_string($discussion->name,true)."</a></font></p>";
					}
					$posthtml .= '<p>';

					$postsarray = $discussionposts[$discussionid];
					sort($postsarray);

					foreach ($postsarray as $postid) {
						$post = $posts[$postid];

						if (array_key_exists($post->userid, $users)) { // we might know him/her already
							$userfrom = $users[$post->userid];
						} else if ($userfrom = get_record('user', 'id', $post->userid)) {
							$users[$userfrom->id] = $userfrom; // fetch only once, we can add it to user list, it will be skipped anyway
						} else {
							mtrace('Could not find user '.$post->userid);
							continue;
						}

						if (!isset($userfrom->groups[$forum->id])) {
							if (!isset($userfrom->groups)) {
								$userfrom->groups = array();
								$users[$userfrom->id]->groups = array();
							}
							$userfrom->groups[$forum->id] = groups_get_all_groups($course->id, $userfrom->id, $cm->groupingid);
							$users[$userfrom->id]->groups[$forum->id] = $userfrom->groups[$forum->id];
						}

						$userfrom->customheaders = array ("Precedence: Bulk");

						if ($userto->maildigest == 2) {
							// Subjects only
							$by = new object();
							$by->name = fullname($userfrom);
							$by->date = userdate($post->modified);
							$posttext .= "\n".format_string($post->subject,true).' '.get_string("bynameondate", "forum", $by);
							$posttext .= "\n---------------------------------------------------------------------";

							$by->name = "<a target=\"_blank\" href=\"$CFG->wwwroot/user/view.php?id=$userfrom->id&amp;course=$course->id\">$by->name</a>";
							$posthtml .= '<div><a target="_blank" href="'.$CFG->wwwroot.'/mod/forum/discuss.php?d='.$discussion->id.'#p'.$post->id.'">'.format_string($post->subject,true).'</a> '.get_string("bynameondate", "forum", $by).'</div>';

						} else {
							// The full treatment
							$posttext .= forum_make_mail_text($course, $forum, $discussion, $post, $userfrom, $userto, true);
							$posthtml .= forum_make_mail_post($course, $forum, $discussion, $post, $userfrom, $userto, false, $canreply, true, false);

						// Create an array of postid's for this user to mark as read.
							if (!$CFG->forum_usermarksread) {
								$userto->markposts[$post->id] = $post->id;
							}
						}
					}
					if ($canunsubscribe) {
						$posthtml .= "\n<div class='mdl-right'><font size=\"1\"><a href=\"$CFG->wwwroot/mod/forum/subscribe.php?id=$forum->id\">".get_string("unsubscribe", "forum")."</a></font></div>";
					} else {
						$posthtml .= "\n<div class='mdl-right'><font size=\"1\">".get_string("everyoneissubscribed", "forum")."</font></div>";
					}
					$posthtml .= '<hr size="1" noshade="noshade" /></p>';
				}
				$posthtml .= '</body>';

				if ($userto->mailformat != 1) {
					// This user DOESN'T want to receive HTML
					$posthtml = '';
				}

				if (!$mailresult =  email_to_user($userto, $site->shortname, $postsubject, $posttext, $posthtml,
												  '', '', $CFG->forum_replytouser)) {
					mtrace("ERROR!");
					echo "Error: mod/forum/cron.php: Could not send out digest mail to user $userto->id ($userto->email)... not trying again.\n";
					add_to_log($course->id, 'forum', 'mail digest error', '', '', $cm->id, $userto->id);
				} else if ($mailresult === 'emailstop') {
					// should not happen anymore - see check above
				} else {
					mtrace("success.");
					$usermailcount++;

					// Mark post as read if forum_usermarksread is set off
					forum_tp_mark_posts_read($userto, $userto->markposts);
				}
			}
		}
	/// We have finishied all digest emails, update $CFG->digestmailtimelast
		set_config('digestmailtimelast', $timenow);
	}

	$USER = $cronuser;
	course_setup(SITEID); // reset cron user language, theme and timezone settings

	if (!empty($usermailcount)) {
		mtrace(get_string('digestsentusers', 'forum', $usermailcount));
	}

	if (!empty($CFG->forum_lastreadclean)) {
		$timenow = time();
		if ($CFG->forum_lastreadclean + (24*3600) < $timenow) {
			set_config('forum_lastreadclean', $timenow);
			mtrace('Removing old forum read tracking info...');
			forum_tp_clean_read_records();
		}
	} else {
		set_config('forum_lastreadclean', time());
	}


	return true;
}

/**
 * Builds and returns the body of the email notification in plain text.
 *
 * @param object $course
 * @param object $forum
 * @param object $discussion
 * @param object $post
 * @param object $userfrom
 * @param object $userto
 * @param boolean $bare
 * @return string The email body in plain text format.
 */
function forum_make_mail_text($course, $forum, $discussion, $post, $userfrom, $userto, $bare = false) {
	global $CFG, $USER;

	if (!isset($userto->viewfullnames[$forum->id])) {
		if (!$cm = get_coursemodule_from_instance('forum', $forum->id, $course->id)) {
			error('Course Module ID was incorrect');
		}
		$modcontext = get_context_instance(CONTEXT_MODULE, $cm->id);
		$viewfullnames = has_capability('moodle/site:viewfullnames', $modcontext, $userto->id);
	} else {
		$viewfullnames = $userto->viewfullnames[$forum->id];
	}

	if (!isset($userto->canpost[$discussion->id])) {
		$modcontext = get_context_instance(CONTEXT_MODULE, $cm->id);
		$canreply = forum_user_can_post($forum, $discussion, $userto, $cm, $course, $modcontext);
	} else {
		$canreply = $userto->canpost[$discussion->id];
	}

	$by = New stdClass;
	$by->name = fullname($userfrom, $viewfullnames);
	$by->date = userdate($post->modified, "", $userto->timezone);

	$strbynameondate = get_string('bynameondate', 'forum', $by);

	$strforums = get_string('forums', 'forum');

	$canunsubscribe = ! forum_is_forcesubscribed($forum);

	$posttext = '';

	if (!$bare) {
		$posttext  = "$course->shortname -> $strforums -> ".format_string($forum->name,true);

		if ($discussion->name != $forum->name) {
			$posttext  .= " -> ".format_string($discussion->name,true);
		}
	}

	$posttext .= "\n---------------------------------------------------------------------\n";
	$posttext .= format_string($post->subject,true);
	if ($bare) {
		$posttext .= " ($CFG->wwwroot/mod/forum/discuss.php?d=$discussion->id#p$post->id)";
	}
	$posttext .= "\n".$strbynameondate."\n";
	$posttext .= "---------------------------------------------------------------------\n";
	$posttext .= format_text_email(trusttext_strip($post->message), $post->format);
	$posttext .= "\n\n";
	if ($post->attachment) {
		$post->course = $course->id;
		$post->forum = $forum->id;
		$posttext .= forum_print_attachments($post, "text");
	}
	if (!$bare && $canreply) {
		$posttext .= "---------------------------------------------------------------------\n";
		$posttext .= get_string("postmailinfo", "forum", $course->shortname)."\n";
		$posttext .= "$CFG->wwwroot/mod/forum/post.php?reply=$post->id\n";
	}
	if (!$bare && $canunsubscribe) {
		$posttext .= "\n---------------------------------------------------------------------\n";
		$posttext .= get_string("unsubscribe", "forum");
		$posttext .= ": $CFG->wwwroot/mod/forum/subscribe.php?id=$forum->id\n";
	}

	return $posttext;
}

/**
 * Builds and returns the body of the email notification in html format.
 *
 * @param object $course
 * @param object $forum
 * @param object $discussion
 * @param object $post
 * @param object $userfrom
 * @param object $userto
 * @return string The email text in HTML format
 */
function forum_make_mail_html($course, $forum, $discussion, $post, $userfrom, $userto) {
	global $CFG;

	if ($userto->mailformat != 1) {  // Needs to be HTML
		return '';
	}

	if (!isset($userto->canpost[$discussion->id])) {
		$canreply = forum_user_can_post($forum, $discussion, $userto);
	} else {
		$canreply = $userto->canpost[$discussion->id];
	}

	$strforums = get_string('forums', 'forum');
	$canunsubscribe = ! forum_is_forcesubscribed($forum);

	$posthtml = '<head>';
	foreach ($CFG->stylesheets as $stylesheet) {
		$posthtml .= '<link rel="stylesheet" type="text/css" href="'.$stylesheet.'" />'."\n";
	}
	$posthtml .= '</head>';
	$posthtml .= "\n<body id=\"email\">\n\n";

	$posthtml .= '<div class="navbar">'.
	'<a target="_blank" href="'.$CFG->wwwroot.'/course/view.php?id='.$course->id.'">'.$course->shortname.'</a> &raquo; '.
	'<a target="_blank" href="'.$CFG->wwwroot.'/mod/forum/index.php?id='.$course->id.'">'.$strforums.'</a> &raquo; '.
	'<a target="_blank" href="'.$CFG->wwwroot.'/mod/forum/view.php?f='.$forum->id.'">'.format_string($forum->name,true).'</a>';
	if ($discussion->name == $forum->name) {
		$posthtml .= '</div>';
	} else {
		$posthtml .= ' &raquo; <a target="_blank" href="'.$CFG->wwwroot.'/mod/forum/discuss.php?d='.$discussion->id.'">'.
					 format_string($discussion->name,true).'</a></div>';
	}
	$posthtml .= forum_make_mail_post($course, $forum, $discussion, $post, $userfrom, $userto, false, $canreply, true, false);

	if ($canunsubscribe) {
		$posthtml .= '<hr /><div class="mdl-align unsubscribelink">
					  <a href="'.$CFG->wwwroot.'/mod/forum/subscribe.php?id='.$forum->id.'">'.get_string('unsubscribe', 'forum').'</a>&nbsp;
					  <a href="'.$CFG->wwwroot.'/mod/forum/unsubscribeall.php">'.get_string('unsubscribeall', 'forum').'</a></div>';
	}

	$posthtml .= '</body>';

	return $posthtml;
}


/**
 *
 * @param object $course
 * @param object $user
 * @param object $mod TODO this is not used in this function, refactor
 * @param object $forum
 * @return object A standard object with 2 variables: info (number of posts for this user) and time (last modified)
 */
function forum_user_outline($course, $user, $mod, $forum) {
	if ($count = forum_count_user_posts($forum->id, $user->id)) {
		if ($count->postcount > 0) {
			$result = new object();
			$result->info = get_string("numposts", "forum", $count->postcount);
			$result->time = $count->lastpost;
			return $result;
		}
	}
	return NULL;
}


/**
 *
 */
function forum_user_complete($course, $user, $mod, $forum) {
	global $CFG,$USER;

	if ($posts = forum_get_user_posts($forum->id, $user->id)) {

		if (!$cm = get_coursemodule_from_instance('forum', $forum->id, $course->id)) {
			error('Course Module ID was incorrect');
		}
		$discussions = forum_get_user_involved_discussions($forum->id, $user->id);

		// preload all user ratings for these discussions - one query only and minimal memory
		$cm->cache->ratings = array();
		$cm->cache->myratings = array();
		if ($postratings = forum_get_all_user_ratings($user->id, $discussions)) {
			foreach ($postratings as $pr) {
				if (!isset($cm->cache->ratings[$pr->postid])) {
					$cm->cache->ratings[$pr->postid] = array();
				}
				$cm->cache->ratings[$pr->postid][$pr->id] = $pr->rating;

				if ($pr->userid == $USER->id) {
					$cm->cache->myratings[$pr->postid] = $pr->rating;
				}
			}
			unset($postratings);
		}

		foreach ($posts as $post) {
			if (!isset($discussions[$post->discussion])) {
				continue;
			}
			$discussion = $discussions[$post->discussion];
			
			$ratings = null;

			if ($forum->assessed) {
				if ($scale = make_grades_menu($forum->scale)) {
					$ratings =new object();
					$ratings->scale = $scale;
					$ratings->assesstimestart = $forum->assesstimestart;
					$ratings->assesstimefinish = $forum->assesstimefinish;
					$ratings->allow = false;
				}
			}

			forum_print_post($post, $discussion, $forum, $cm, $course, false, false, false, $ratings);

		}
	} else {
		echo "<p>".get_string("noposts", "forum")."</p>";
	}
}


/**
 *
 */
function forum_print_overview($courses,&$htmlarray) {
	global $USER, $CFG;
	$LIKE = sql_ilike();

	if (empty($courses) || !is_array($courses) || count($courses) == 0) {
		return array();
	}

	if (!$forums = get_all_instances_in_courses('forum',$courses)) {
		return;
	}


	// get all forum logs in ONE query (much better!)
	$sql = "SELECT instance,cmid,l.course,COUNT(l.id) as count FROM {$CFG->prefix}log l "
		." JOIN {$CFG->prefix}course_modules cm ON cm.id = cmid "
		." WHERE (";
	foreach ($courses as $course) {
		$sql .= '(l.course = '.$course->id.' AND l.time > '.$course->lastaccess.') OR ';
	}
	$sql = substr($sql,0,-3); // take off the last OR

	$sql .= ") AND l.module = 'forum' AND action $LIKE 'add post%' "
		." AND userid != ".$USER->id." GROUP BY cmid,l.course,instance";

	if (!$new = get_records_sql($sql)) {
		$new = array(); // avoid warnings
	}

	// also get all forum tracking stuff ONCE.
	$trackingforums = array();
	foreach ($forums as $forum) {
		if (forum_tp_can_track_forums($forum)) {
			$trackingforums[$forum->id] = $forum;
		}
	}

	if (count($trackingforums) > 0) {
		$cutoffdate = isset($CFG->forum_oldpostdays) ? (time() - ($CFG->forum_oldpostdays*24*60*60)) : 0;
		$sql = 'SELECT d.forum,d.course,COUNT(p.id) AS count '.
			' FROM '.$CFG->prefix.'forum_posts p '.
			' JOIN '.$CFG->prefix.'forum_discussions d ON p.discussion = d.id '.
			' LEFT JOIN '.$CFG->prefix.'forum_read r ON r.postid = p.id AND r.userid = '.$USER->id.' WHERE (';
		foreach ($trackingforums as $track) {
			$sql .= '(d.forum = '.$track->id.' AND (d.groupid = -1 OR d.groupid = 0 OR d.groupid = '.get_current_group($track->course).')) OR ';
		}
		$sql = substr($sql,0,-3); // take off the last OR
		$sql .= ') AND p.modified >= '.$cutoffdate.' AND r.id is NULL GROUP BY d.forum,d.course';

		if (!$unread = get_records_sql($sql)) {
			$unread = array();
		}
	} else {
		$unread = array();
	}

	if (empty($unread) and empty($new)) {
		return;
	}

	$strforum = get_string('modulename','forum');
	$strnumunread = get_string('overviewnumunread','forum');
	$strnumpostssince = get_string('overviewnumpostssince','forum');

	foreach ($forums as $forum) {
		$str = '';
		$count = 0;
		$thisunread = 0;
		$showunread = false;
		// either we have something from logs, or trackposts, or nothing.
		if (array_key_exists($forum->id, $new) && !empty($new[$forum->id])) {
			$count = $new[$forum->id]->count;
		}
		if (array_key_exists($forum->id,$unread)) {
			$thisunread = $unread[$forum->id]->count;
			$showunread = true;
		}
		if ($count > 0 || $thisunread > 0) {
			$str .= '<div class="overview forum"><div class="name">'.$strforum.': <a title="'.$strforum.'" href="'.$CFG->wwwroot.'/mod/forum/view.php?f='.$forum->id.'">'.
				$forum->name.'</a></div>';
			$str .= '<div class="info">';
			$str .= $count.' '.$strnumpostssince;
			if (!empty($showunread)) {
				$str .= '<br />'.$thisunread .' '.$strnumunread;
			}
			$str .= '</div></div>';
		}
		if (!empty($str)) {
			if (!array_key_exists($forum->course,$htmlarray)) {
				$htmlarray[$forum->course] = array();
			}
			if (!array_key_exists('forum',$htmlarray[$forum->course])) {
				$htmlarray[$forum->course]['forum'] = ''; // initialize, avoid warnings
			}
			$htmlarray[$forum->course]['forum'] .= $str;
		}
	}
}

/**
 * Given a course and a date, prints a summary of all the new
 * messages posted in the course since that date
 * @param object $course
 * @param bool $viewfullnames capability
 * @param int $timestart
 * @return bool success
 */
function forum_print_recent_activity($course, $viewfullnames, $timestart) {
	global $CFG, $USER;

	// do not use log table if possible, it may be huge and is expensive to join with other tables

	if (!$posts = get_records_sql("SELECT p.*, f.type AS forumtype, d.forum, d.groupid,
										  d.timestart, d.timeend, d.userid AS duserid,
										  u.firstname, u.lastname, u.email, u.picture
									 FROM {$CFG->prefix}forum_posts p
										  JOIN {$CFG->prefix}forum_discussions d ON d.id = p.discussion
										  JOIN {$CFG->prefix}forum f			 ON f.id = d.forum
										  JOIN {$CFG->prefix}user u			  ON u.id = p.userid
									WHERE p.created > $timestart AND f.course = {$course->id}
								 ORDER BY p.id ASC")) { // order by initial posting date
		 return false;
	}

	$modinfo =& get_fast_modinfo($course);

	$groupmodes = array();
	$cms	= array();

	$strftimerecent = get_string('strftimerecent');

	$printposts = array();
	foreach ($posts as $post) {
		if (!isset($modinfo->instances['forum'][$post->forum])) {
			// not visible
			continue;
		}
		$cm = $modinfo->instances['forum'][$post->forum];
		if (!$cm->uservisible) {
			continue;
		}
		$context = get_context_instance(CONTEXT_MODULE, $cm->id);

		if (!has_capability('mod/forum:viewdiscussion', $context)) {
			continue;
		}

		if (!empty($CFG->forum_enabletimedposts) and $USER->id != $post->duserid
		  and (($post->timestart > 0 and $post->timestart > time()) or ($post->timeend > 0 and $post->timeend < time()))) {
			if (!has_capability('mod/forum:viewhiddentimedposts', $context)) {
				continue;
			}
		}

		$groupmode = groups_get_activity_groupmode($cm, $course);

		if ($groupmode) {
			if ($post->groupid == -1 or $groupmode == VISIBLEGROUPS or has_capability('moodle/site:accessallgroups', $context)) {
				// oki (Open discussions have groupid -1)
			} else {
				// separate mode
				if (isguestuser()) {
					// shortcut
					continue;
				}

				if (is_null($modinfo->groups)) {
					$modinfo->groups = groups_get_user_groups($course->id); // load all my groups and cache it in modinfo
				}

				if (!array_key_exists($post->groupid, $modinfo->groups[0])) {
					continue;
				}
			}
		}

		$printposts[] = $post;
	}
	unset($posts);

	if (!$printposts) {
		return false;
	}

	print_headline(get_string('newforumposts', 'forum').':', 3);
	echo "\n<ul class='unlist'>\n";

	foreach ($printposts as $post) {
		$subjectclass = empty($post->parent) ? ' bold' : '';

		echo '<li><div class="head">'.
			   '<div class="date">'.userdate($post->modified, $strftimerecent).'</div>'.
			   '<div class="name">'.fullname($post, $viewfullnames).'</div>'.
			 '</div>';
		echo '<div class="info'.$subjectclass.'">';
		if (empty($post->parent)) {
			echo '"<a href="'.$CFG->wwwroot.'/mod/forum/discuss.php?d='.$post->discussion.'">';
		} else {
			echo '"<a href="'.$CFG->wwwroot.'/mod/forum/discuss.php?d='.$post->discussion.'&amp;parent='.$post->parent.'#p'.$post->id.'">';
		}
		$post->subject = break_up_long_words(format_string($post->subject, true));
		echo $post->subject;
		echo "</a>\"</div></li>\n";
	}

	echo "</ul>\n";

	return true;
}

/**
 * Return grade for given user or all users.
 *
 * @param int $forumid id of forum
 * @param int $userid optional user id, 0 means all users
 * @return array array of grades, false if none
 */
function forum_get_user_grades($forum, $userid=0) {
	global $CFG;

	$user = $userid ? "AND u.id = $userid" : "";

	$aggtype = $forum->assessed;
	switch ($aggtype) {
		case FORUM_AGGREGATE_COUNT :
			$sql = "SELECT u.id, u.id AS userid, COUNT(fr.rating) AS rawgrade
					  FROM {$CFG->prefix}user u, {$CFG->prefix}forum_posts fp,
						   {$CFG->prefix}forum_ratings fr, {$CFG->prefix}forum_discussions fd
					 WHERE u.id = fp.userid AND fp.discussion = fd.id AND fr.post = fp.id
						   AND fr.userid != u.id AND fd.forum = $forum->id
						   $user
				  GROUP BY u.id";
			break;
		case FORUM_AGGREGATE_MAX :
			$sql = "SELECT u.id, u.id AS userid, MAX(fr.rating) AS rawgrade
					  FROM {$CFG->prefix}user u, {$CFG->prefix}forum_posts fp,
						   {$CFG->prefix}forum_ratings fr, {$CFG->prefix}forum_discussions fd
					 WHERE u.id = fp.userid AND fp.discussion = fd.id AND fr.post = fp.id
						   AND fr.userid != u.id AND fd.forum = $forum->id
						   $user
				  GROUP BY u.id";
			break;
		case FORUM_AGGREGATE_MIN :
			$sql = "SELECT u.id, u.id AS userid, MIN(fr.rating) AS rawgrade
					  FROM {$CFG->prefix}user u, {$CFG->prefix}forum_posts fp,
						   {$CFG->prefix}forum_ratings fr, {$CFG->prefix}forum_discussions fd
					 WHERE u.id = fp.userid AND fp.discussion = fd.id AND fr.post = fp.id
						   AND fr.userid != u.id AND fd.forum = $forum->id
						   $user
				  GROUP BY u.id";
			break;
		case FORUM_AGGREGATE_SUM :
			$sql = "SELECT u.id, u.id AS userid, SUM(fr.rating) AS rawgrade
					 FROM {$CFG->prefix}user u, {$CFG->prefix}forum_posts fp,
						  {$CFG->prefix}forum_ratings fr, {$CFG->prefix}forum_discussions fd
					WHERE u.id = fp.userid AND fp.discussion = fd.id AND fr.post = fp.id
						  AND fr.userid != u.id AND fd.forum = $forum->id
						  $user
				 GROUP BY u.id";
			break;
		default : //avg
			$sql = "SELECT u.id, u.id AS userid, AVG(fr.rating) AS rawgrade
					  FROM {$CFG->prefix}user u, {$CFG->prefix}forum_posts fp,
						   {$CFG->prefix}forum_ratings fr, {$CFG->prefix}forum_discussions fd
					 WHERE u.id = fp.userid AND fp.discussion = fd.id AND fr.post = fp.id
						   AND fr.userid != u.id AND fd.forum = $forum->id
						   $user
				  GROUP BY u.id";
			break;
	}

	if ($results = get_records_sql($sql)) {
		// it could throw off the grading if count and sum returned a rawgrade higher than scale
		// so to prevent it we review the results and ensure that rawgrade does not exceed the scale, if it does we set rawgrade = scale (i.e. full credit)
		foreach ($results as $rid=>$result) {
			if ($forum->scale >= 0) {
				//numeric
				if ($result->rawgrade > $forum->scale) {
					$results[$rid]->rawgrade = $forum->scale;
				}
			} else {
				//scales
				if ($scale = get_record('scale', 'id', -$forum->scale)) {
					$scale = explode(',', $scale->scale);
					$max = count($scale);
					if ($result->rawgrade > $max) {
						$results[$rid]->rawgrade = $max;
					}
				}
			}
		}
	}

	return $results;
}

/**
 * Update grades by firing grade_updated event
 *
 * @param object $forum null means all forums
 * @param int $userid specific user only, 0 mean all
 * @param boolean $nullifnone return null if grade does not exist
 * @return void
 */
function forum_update_grades($forum=null, $userid=0, $nullifnone=true) {
	global $CFG;

	if ($forum != null) {
		require_once($CFG->libdir.'/gradelib.php');
		if ($grades = forum_get_user_grades($forum, $userid)) {
			forum_grade_item_update($forum, $grades);

		} else if ($userid and $nullifnone) {
			$grade = new object();
			$grade->userid   = $userid;
			$grade->rawgrade = NULL;
			forum_grade_item_update($forum, $grade);

		} else {
			forum_grade_item_update($forum);
		}

	} else {
		$sql = "SELECT f.*, cm.idnumber as cmidnumber
				  FROM {$CFG->prefix}forum f, {$CFG->prefix}course_modules cm, {$CFG->prefix}modules m
				 WHERE m.name='forum' AND m.id=cm.module AND cm.instance=f.id";
		if ($rs = get_recordset_sql($sql)) {
			while ($forum = rs_fetch_next_record($rs)) {
				if ($forum->assessed) {
					forum_update_grades($forum, 0, false);
				} else {
					forum_grade_item_update($forum);
				}
			}
			rs_close($rs);
		}
	}
}

/**
 * Create/update grade item for given forum
 *
 * @param object $forum object with extra cmidnumber
 * @param mixed optional array/object of grade(s); 'reset' means reset grades in gradebook
 * @return int 0 if ok
 */
function forum_grade_item_update($forum, $grades=NULL) {
	global $CFG;
	if (!function_exists('grade_update')) { //workaround for buggy PHP versions
		require_once($CFG->libdir.'/gradelib.php');
	}

	$params = array('itemname'=>$forum->name, 'idnumber'=>$forum->cmidnumber);

	if (!$forum->assessed or $forum->scale == 0) {
		$params['gradetype'] = GRADE_TYPE_NONE;

	} else if ($forum->scale > 0) {
		$params['gradetype'] = GRADE_TYPE_VALUE;
		$params['grademax']  = $forum->scale;
		$params['grademin']  = 0;

	} else if ($forum->scale < 0) {
		$params['gradetype'] = GRADE_TYPE_SCALE;
		$params['scaleid']   = -$forum->scale;
	}

	if ($grades  === 'reset') {
		$params['reset'] = true;
		$grades = NULL;
	}

	return grade_update('mod/forum', $forum->course, 'mod', 'forum', $forum->id, 0, $grades, $params);
}

/**
 * Delete grade item for given forum
 *
 * @param object $forum object
 * @return object grade_item
 */
function forum_grade_item_delete($forum) {
	global $CFG;
	require_once($CFG->libdir.'/gradelib.php');

	return grade_update('mod/forum', $forum->course, 'mod', 'forum', $forum->id, 0, NULL, array('deleted'=>1));
}


/**
 * Returns the users with data in one forum
 * (users with records in forum_subscriptions, forum_posts and forum_ratings, students)
 * @param int $forumid
 * @return mixed array or false if none
 */
function forum_get_participants($forumid) {

	global $CFG;

	//Get students from forum_subscriptions
	$st_subscriptions = get_records_sql("SELECT DISTINCT u.id, u.id
										 FROM {$CFG->prefix}user u,
											  {$CFG->prefix}forum_subscriptions s
										 WHERE s.forum = '$forumid' and
											   u.id = s.userid");
	//Get students from forum_posts
	$st_posts = get_records_sql("SELECT DISTINCT u.id, u.id
								 FROM {$CFG->prefix}user u,
									  {$CFG->prefix}forum_discussions d,
									  {$CFG->prefix}forum_posts p
								 WHERE d.forum = '$forumid' and
									   p.discussion = d.id and
									   u.id = p.userid");

	//Get students from forum_ratings
	$st_ratings = get_records_sql("SELECT DISTINCT u.id, u.id
								   FROM {$CFG->prefix}user u,
										{$CFG->prefix}forum_discussions d,
										{$CFG->prefix}forum_posts p,
										{$CFG->prefix}forum_ratings r
								   WHERE d.forum = '$forumid' and
										 p.discussion = d.id and
										 r.post = p.id and
										 u.id = r.userid");

	//Add st_posts to st_subscriptions
	if ($st_posts) {
		foreach ($st_posts as $st_post) {
			$st_subscriptions[$st_post->id] = $st_post;
		}
	}
	//Add st_ratings to st_subscriptions
	if ($st_ratings) {
		foreach ($st_ratings as $st_rating) {
			$st_subscriptions[$st_rating->id] = $st_rating;
		}
	}
	//Return st_subscriptions array (it contains an array of unique users)
	return ($st_subscriptions);
}

/**
 * This function returns if a scale is being used by one forum
 * @param int $forumid
 * @param int $scaleid negative number
 * @return bool
 */
function forum_scale_used ($forumid,$scaleid) {

	$return = false;

	$rec = get_record("forum","id","$forumid","scale","-$scaleid");

	if (!empty($rec) && !empty($scaleid)) {
		$return = true;
	}

	return $return;
}

/**
 * Checks if scale is being used by any instance of forum
 *
 * This is used to find out if scale used anywhere
 * @param $scaleid int
 * @return boolean True if the scale is used by any forum
 */
function forum_scale_used_anywhere($scaleid) {
	if ($scaleid and record_exists('forum', 'scale', -$scaleid)) {
		return true;
	} else {
		return false;
	}
}

// SQL FUNCTIONS ///////////////////////////////////////////////////////////

/**
 * Gets a post with all info ready for forum_print_post
 * Most of these joins are just to get the forum id
 * @param int $postid
 * @return mixed array of posts or false
 */
function forum_get_post_full($postid) {
	global $CFG;

	return get_record_sql("SELECT p.*, d.forum, u.firstname, u.lastname, u.email, u.picture, u.imagealt
							 FROM {$CFG->prefix}forum_posts p
								  JOIN {$CFG->prefix}forum_discussions d ON p.discussion = d.id
								  LEFT JOIN {$CFG->prefix}user u ON p.userid = u.id
							WHERE p.id = '$postid'");
}

/**
 * Gets posts with all info ready for forum_print_post
 * We pass forumid in because we always know it so no need to make a
 * complicated join to find it out.
 * @return mixed array of posts or false
 */
function forum_get_discussion_posts($discussion, $sort, $forumid) {
	global $CFG;

	return get_records_sql("SELECT p.*, $forumid AS forum, u.firstname, u.lastname, u.email, u.picture, u.imagealt
							  FROM {$CFG->prefix}forum_posts p
						 LEFT JOIN {$CFG->prefix}user u ON p.userid = u.id
							 WHERE p.discussion = $discussion
							   AND p.parent > 0 $sort");
}

/**
 * Gets all posts in discussion including top parent.
 * @param int $discussionid
 * @param string $sort
 * @param bool $tracking does user track the forum?
 * @return array of posts
 */
function forum_get_all_discussion_posts($discussionid, $sort, $tracking=false) {
	global $CFG, $USER;

	$tr_sel  = "";
	$tr_join = "";

	if ($tracking) {
		$now = time();
		$cutoffdate = $now - ($CFG->forum_oldpostdays * 24 * 3600);
		$tr_sel  = ", fr.id AS postread";
		$tr_join = "LEFT JOIN {$CFG->prefix}forum_read fr ON (fr.postid = p.id AND fr.userid = $USER->id)";
	}

	if (!$posts = get_records_sql("SELECT p.*, u.firstname, u.lastname, u.email, u.picture, u.imagealt $tr_sel
									 FROM {$CFG->prefix}forum_posts p
										  LEFT JOIN {$CFG->prefix}user u ON p.userid = u.id
										  $tr_join
									WHERE p.discussion = $discussionid
								 ORDER BY $sort")) {
		return array();
	}

	foreach ($posts as $pid=>$p) {
		if ($tracking) {
			if (forum_tp_is_post_old($p)) {
				 $posts[$pid]->postread = true;
			}
		}
		if (!$p->parent) {
			continue;
		}
		if (!isset($posts[$p->parent])) {
			continue; // parent does not exist??
		}
		if (!isset($posts[$p->parent]->children)) {
			$posts[$p->parent]->children = array();
		}
		$posts[$p->parent]->children[$pid] =& $posts[$pid];
	}

	return $posts;
}

/**
 * Gets posts with all info ready for forum_print_post
 * We pass forumid in because we always know it so no need to make a
 * complicated join to find it out.
 */
function forum_get_child_posts($parent, $forumid) {
	global $CFG;

	return get_records_sql("SELECT p.*, $forumid AS forum, u.firstname, u.lastname, u.email, u.picture, u.imagealt
							  FROM {$CFG->prefix}forum_posts p
						 LEFT JOIN {$CFG->prefix}user u ON p.userid = u.id
							 WHERE p.parent = '$parent'
						  ORDER BY p.created ASC");
}

/**
 * An array of forum objects that the user is allowed to read/search through.
 * @param $userid
 * @param $courseid - if 0, we look for forums throughout the whole site.
 * @return array of forum objects, or false if no matches
 *		 Forum objects have the following attributes:
 *		 id, type, course, cmid, cmvisible, cmgroupmode, accessallgroups,
 *		 viewhiddentimedposts
 */
function forum_get_readable_forums($userid, $courseid=0) {

	global $CFG, $USER;
	require_once($CFG->dirroot.'/course/lib.php');

	if (!$forummod = get_record('modules', 'name', 'forum')) {
		error('The forum module is not installed');
	}

	if ($courseid) {
		$courses = get_records('course', 'id', $courseid);
	} else {
		// If no course is specified, then the user can see SITE + his courses.
		// And admins can see all courses, so pass the $doanything flag enabled
		$courses1 = get_records('course', 'id', SITEID);
		$courses2 = get_my_courses($userid, null, null, true);
		$courses = array_merge($courses1, $courses2);
	}
	if (!$courses) {
		return array();
	}

	$readableforums = array();

	foreach ($courses as $course) {

		$modinfo =& get_fast_modinfo($course);
		if (is_null($modinfo->groups)) {
			$modinfo->groups = groups_get_user_groups($course->id, $userid);
		}

		if (empty($modinfo->instances['forum'])) {
			// hmm, no forums?
			continue;
		}

		$courseforums = get_records('forum', 'course', $course->id);

		foreach ($modinfo->instances['forum'] as $forumid => $cm) {
			if (!$cm->uservisible or !isset($courseforums[$forumid])) {
				continue;
			}
			$context = get_context_instance(CONTEXT_MODULE, $cm->id);
			$forum = $courseforums[$forumid];

			if (!has_capability('mod/forum:viewdiscussion', $context)) {
				continue;
			}

		 /// group access
			if (groups_get_activity_groupmode($cm, $course) == SEPARATEGROUPS and !has_capability('moodle/site:accessallgroups', $context)) {
				if (is_null($modinfo->groups)) {
					$modinfo->groups = groups_get_user_groups($course->id, $USER->id);
				}
				if (empty($CFG->enablegroupings)) {
					$forum->onlygroups = $modinfo->groups[0];
					$forum->onlygroups[] = -1;
				} else if (isset($modinfo->groups[$cm->groupingid])) {
					$forum->onlygroups = $modinfo->groups[$cm->groupingid];
					$forum->onlygroups[] = -1;
				} else {
					$forum->onlygroups = array(-1);
				}
			}

		/// hidden timed discussions
			$forum->viewhiddentimedposts = true;
			if (!empty($CFG->forum_enabletimedposts)) {
				if (!has_capability('mod/forum:viewhiddentimedposts', $context)) {
					$forum->viewhiddentimedposts = false;
				}
			}

		/// qanda access
			if ($forum->type == 'qanda'
					&& !has_capability('mod/forum:viewqandawithoutposting', $context)) {

				// We need to check whether the user has posted in the qanda forum.
				$forum->onlydiscussions = array();  // Holds discussion ids for the discussions
													// the user is allowed to see in this forum.
				if ($discussionspostedin = forum_discussions_user_has_posted_in($forum->id, $USER->id)) {
					foreach ($discussionspostedin as $d) {
						$forum->onlydiscussions[] = $d->id;
					}
				}
			}

			$readableforums[$forum->id] = $forum;
		}

		unset($modinfo);

	} // End foreach $courses

	//print_object($courses);
	//print_object($readableforums);

	return $readableforums;
}

/**
 * Returns a list of posts found using an array of search terms.
 * @param $searchterms - array of search terms, e.g. word +word -word
 * @param $courseid - if 0, we search through the whole site
 * @param $page
 * @param $recordsperpage=50
 * @param &$totalcount
 * @param $extrasql
 * @return array of posts found
 */
function forum_search_posts($searchterms, $courseid=0, $limitfrom=0, $limitnum=50,
							&$totalcount, $extrasql='') {
	global $CFG, $USER;
	require_once($CFG->libdir.'/searchlib.php');

	$forums = forum_get_readable_forums($USER->id, $courseid);

	if (count($forums) == 0) {
		$totalcount = 0;
		return false;
	}

	$now = round(time(), -2); // db friendly

	$fullaccess = array();
	$where = array();

	foreach ($forums as $forumid => $forum) {
		$select = array();

		if (!$forum->viewhiddentimedposts) {
			$select[] = "(d.userid = {$USER->id} OR (d.timestart < $now AND (d.timeend = 0 OR d.timeend > $now)))";
		}

		if ($forum->type == 'qanda') {
			if (!empty($forum->onlydiscussions)) {
				$discussionsids = implode(',', $forum->onlydiscussions);
				$select[] = "(d.id IN ($discussionsids) OR p.parent = 0)";
			} else {
				$select[] = "p.parent = 0";
			}
		}

		if (!empty($forum->onlygroups)) {
			$groupids = implode(',', $forum->onlygroups);
			$select[] = "d.groupid IN ($groupids)";
		}

		if ($select) {
			$selects = implode(" AND ", $select);
			$where[] = "(d.forum = $forumid AND $selects)";
		} else {
			$fullaccess[] = $forumid;
		}
	}

	if ($fullaccess) {
		$fullids = implode(',', $fullaccess);
		$where[] = "(d.forum IN ($fullids))";
	}

	$selectdiscussion = "(".implode(" OR ", $where).")";

	// Some differences SQL
	$LIKE = sql_ilike();
	$NOTLIKE = 'NOT ' . $LIKE;
	if ($CFG->dbfamily == 'postgres') {
		$REGEXP = '~*';
		$NOTREGEXP = '!~*';
	} else {
		$REGEXP = 'REGEXP';
		$NOTREGEXP = 'NOT REGEXP';
	}

	$messagesearch = '';
	$searchstring = '';

	// Need to concat these back together for parser to work.
	foreach($searchterms as $searchterm){
		if ($searchstring != '') {
			$searchstring .= ' ';
		}
		$searchstring .= $searchterm;
	}

	// We need to allow quoted strings for the search. The quotes *should* be stripped
	// by the parser, but this should be examined carefully for security implications.
	$searchstring = str_replace("\\\"","\"",$searchstring);
	$parser = new search_parser();
	$lexer = new search_lexer($parser);

	if ($lexer->parse($searchstring)) {
		$parsearray = $parser->get_parsed_array();
	// Experimental feature under 1.8! MDL-8830
	// Use alternative text searches if defined
	// This feature only works under mysql until properly implemented for other DBs
	// Requires manual creation of text index for forum_posts before enabling it:
	// CREATE FULLTEXT INDEX foru_post_tix ON [prefix]forum_posts (subject, message)
	// Experimental feature under 1.8! MDL-8830
		if (!empty($CFG->forum_usetextsearches)) {
			$messagesearch = search_generate_text_SQL($parsearray, 'p.message', 'p.subject',
												 'p.userid', 'u.id', 'u.firstname',
												 'u.lastname', 'p.modified', 'd.forum');
		} else {
			$messagesearch = search_generate_SQL($parsearray, 'p.message', 'p.subject',
												 'p.userid', 'u.id', 'u.firstname',
												 'u.lastname', 'p.modified', 'd.forum');
		}
	}

	$fromsql = "{$CFG->prefix}forum_posts p,
				  {$CFG->prefix}forum_discussions d,
				  {$CFG->prefix}user u";

	$selectsql = " $messagesearch
			   AND p.discussion = d.id
			   AND p.userid = u.id
			   AND $selectdiscussion
				   $extrasql";

	$countsql = "SELECT COUNT(*)
				   FROM $fromsql
				  WHERE $selectsql";

	$searchsql = "SELECT p.*,
						 d.forum,
						 u.firstname,
						 u.lastname,
						 u.email,
						 u.picture,
						 u.imagealt
					FROM $fromsql
				   WHERE $selectsql
				ORDER BY p.modified DESC";

	$totalcount = count_records_sql($countsql);

	return get_records_sql($searchsql, $limitfrom, $limitnum);
}

/**
 * Returns a list of ratings for all posts in discussion
 * @param object $discussion
 * @return array of ratings or false
 */
function forum_get_all_discussion_ratings($discussion) {
	global $CFG;
	return get_records_sql("SELECT r.id, r.userid, p.id AS postid, r.rating
							  FROM {$CFG->prefix}forum_ratings r,
								   {$CFG->prefix}forum_posts p
							 WHERE r.post = p.id AND p.discussion = $discussion->id
							 ORDER BY p.id ASC");
}

/**
 * Returns a list of ratings for one specific user for all posts in discussion
 * @global object $CFG
 * @param object $discussions the discussions for which we return all ratings
 * @param int $userid the user for who we return all ratings
 * @return object
 */
function forum_get_all_user_ratings($userid, $discussions) {
	global $CFG;


	foreach ($discussions as $discussion) {
	 if (!isset($discussionsid)){
		 $discussionsid = $discussion->id;
	 }
	 else {
		 $discussionsid .= ",".$discussion->id;
	 }
	}

	$sql = "SELECT r.id, r.userid, p.id AS postid, r.rating
							  FROM {$CFG->prefix}forum_ratings r,
								   {$CFG->prefix}forum_posts p
							 WHERE r.post = p.id AND p.userid = $userid";
	//postgres compability
	if (!isset($discussionsid)) {
	   $sql .=" AND p.discussion IN (".$discussionsid.")";
	}
	$sql .=" ORDER BY p.id ASC";

	return get_records_sql($sql);
	

}

/**
 * Returns a list of ratings for a particular post - sorted.
 * @param int $postid
 * @param string $sort
 * @return array of ratings or false
 */
function forum_get_ratings($postid, $sort="u.firstname ASC") {
	global $CFG;
	return get_records_sql("SELECT u.*, r.rating, r.time
							  FROM {$CFG->prefix}forum_ratings r,
								   {$CFG->prefix}user u
							 WHERE r.post = '$postid'
							   AND r.userid = u.id
							 ORDER BY $sort");
}

/**
 * Returns a list of all new posts that have not been mailed yet
 * @param int $starttime - posts created after this time
 * @param int $endtime - posts created before this
 * @param int $now - used for timed discussions only
 */
function forum_get_unmailed_posts($starttime, $endtime, $now=null) {
	global $CFG;

	if (!empty($CFG->forum_enabletimedposts)) {
		if (empty($now)) {
			$now = time();
		}
		$timedsql = "AND (d.timestart < $now AND (d.timeend = 0 OR d.timeend > $now))";
	} else {
		$timedsql = "";
	}

	return get_records_sql("SELECT p.*, d.course, d.forum
							  FROM {$CFG->prefix}forum_posts p
								   JOIN {$CFG->prefix}forum_discussions d ON d.id = p.discussion
							 WHERE p.mailed = 0
								   AND p.created >= $starttime
								   AND (p.created < $endtime OR p.mailnow = 1)
								   $timedsql
						  ORDER BY p.modified ASC");
}

/**
 * Marks posts before a certain time as being mailed already
 */
function forum_mark_old_posts_as_mailed($endtime, $now=null) {
	global $CFG;
	if (empty($now)) {
		$now = time();
	}

	if (empty($CFG->forum_enabletimedposts)) {
		return execute_sql("UPDATE {$CFG->prefix}forum_posts
							   SET mailed = '1'
							 WHERE (created < $endtime OR mailnow = 1)
								   AND mailed = 0", false);

	} else {
		return execute_sql("UPDATE {$CFG->prefix}forum_posts
							   SET mailed = '1'
							 WHERE discussion NOT IN (SELECT d.id
														FROM {$CFG->prefix}forum_discussions d
													   WHERE d.timestart > $now)
								   AND (created < $endtime OR mailnow = 1)
								   AND mailed = 0", false);
	}
}

/**
 * Get all the posts for a user in a forum suitable for forum_print_post
 */
function forum_get_user_posts($forumid, $userid) {
	global $CFG;

	$timedsql = "";
	if (!empty($CFG->forum_enabletimedposts)) {
		$cm = get_coursemodule_from_instance('forum', $forumid);
		if (!has_capability('mod/forum:viewhiddentimedposts' , get_context_instance(CONTEXT_MODULE, $cm->id))) {
			$now = time();
			$timedsql = "AND (d.timestart < $now AND (d.timeend = 0 OR d.timeend > $now))";
		}
	}

	return get_records_sql("SELECT p.*, d.forum, u.firstname, u.lastname, u.email, u.picture, u.imagealt
							  FROM {$CFG->prefix}forum f
								   JOIN {$CFG->prefix}forum_discussions d ON d.forum = f.id
								   JOIN {$CFG->prefix}forum_posts p	   ON p.discussion = d.id
								   JOIN {$CFG->prefix}user u			  ON u.id = p.userid
							 WHERE f.id = $forumid
								   AND p.userid = $userid
								   $timedsql
						  ORDER BY p.modified ASC");
}

/**
 * Get all the discussions user participated in
 * @param int $forumid
 * @param int $userid
 * @return array or false
 */
function forum_get_user_involved_discussions($forumid, $userid) {
	global $CFG;

	$timedsql = "";
	if (!empty($CFG->forum_enabletimedposts)) {
		$cm = get_coursemodule_from_instance('forum', $forumid);
		if (!has_capability('mod/forum:viewhiddentimedposts' , get_context_instance(CONTEXT_MODULE, $cm->id))) {
			$now = time();
			$timedsql = "AND (d.timestart < $now AND (d.timeend = 0 OR d.timeend > $now))";
		}
	}

	return get_records_sql("SELECT DISTINCT d.*
							  FROM {$CFG->prefix}forum f
								   JOIN {$CFG->prefix}forum_discussions d ON d.forum = f.id
								   JOIN {$CFG->prefix}forum_posts p	   ON p.discussion = d.id
							 WHERE f.id = $forumid
								   AND p.userid = $userid
								   $timedsql");
}

/**
 * Get all the posts for a user in a forum suitable for forum_print_post
 * @param int $forumid
 * @param int $userid
 * @return array of counts or false
 */
function forum_count_user_posts($forumid, $userid) {
	global $CFG;

	$timedsql = "";
	if (!empty($CFG->forum_enabletimedposts)) {
		$cm = get_coursemodule_from_instance('forum', $forumid);
		if (!has_capability('mod/forum:viewhiddentimedposts' , get_context_instance(CONTEXT_MODULE, $cm->id))) {
			$now = time();
			$timedsql = "AND (d.timestart < $now AND (d.timeend = 0 OR d.timeend > $now))";
		}
	}

	return get_record_sql("SELECT COUNT(p.id) AS postcount, MAX(p.modified) AS lastpost
							 FROM {$CFG->prefix}forum f
								  JOIN {$CFG->prefix}forum_discussions d ON d.forum = f.id
								  JOIN {$CFG->prefix}forum_posts p	   ON p.discussion = d.id
								  JOIN {$CFG->prefix}user u			  ON u.id = p.userid
							WHERE f.id = $forumid
								  AND p.userid = $userid
								  $timedsql");
}

/**
 * Given a log entry, return the forum post details for it.
 */
function forum_get_post_from_log($log) {
	global $CFG;

	if ($log->action == "add post") {

		return get_record_sql("SELECT p.*, f.type AS forumtype, d.forum, d.groupid,
										   u.firstname, u.lastname, u.email, u.picture
								 FROM {$CFG->prefix}forum_discussions d,
									  {$CFG->prefix}forum_posts p,
									  {$CFG->prefix}forum f,
									  {$CFG->prefix}user u
								WHERE p.id = '$log->info'
								  AND d.id = p.discussion
								  AND p.userid = u.id
								  AND u.deleted <> '1'
								  AND f.id = d.forum");


	} else if ($log->action == "add discussion") {

		return get_record_sql("SELECT p.*, f.type AS forumtype, d.forum, d.groupid,
										   u.firstname, u.lastname, u.email, u.picture
								 FROM {$CFG->prefix}forum_discussions d,
									  {$CFG->prefix}forum_posts p,
									  {$CFG->prefix}forum f,
									  {$CFG->prefix}user u
								WHERE d.id = '$log->info'
								  AND d.firstpost = p.id
								  AND p.userid = u.id
								  AND u.deleted <> '1'
								  AND f.id = d.forum");
	}
	return NULL;
}

/**
 * Given a discussion id, return the first post from the discussion
 */
function forum_get_firstpost_from_discussion($discussionid) {
	global $CFG;

	return get_record_sql("SELECT p.*
							 FROM {$CFG->prefix}forum_discussions d,
								  {$CFG->prefix}forum_posts p
							WHERE d.id = '$discussionid'
							  AND d.firstpost = p.id ");
}

/**
 * Returns an array of counts of replies to each discussion
 */
function forum_count_discussion_replies($forumid, $forumsort="", $limit=-1, $page=-1, $perpage=0) {
	global $CFG;

	if ($limit > 0) {
		$limitfrom = 0;
		$limitnum  = $limit;
	} else if ($page != -1) {
		$limitfrom = $page*$perpage;
		$limitnum  = $perpage;
	} else {
		$limitfrom = 0;
		$limitnum  = 0;
	}

	if ($forumsort == "") {
		$orderby = "";
		$groupby = "";

	} else {
		$orderby = "ORDER BY $forumsort";
		$groupby = ", ".strtolower($forumsort);
		$groupby = str_replace('desc', '', $groupby);
		$groupby = str_replace('asc', '', $groupby);
	}

	if (($limitfrom == 0 and $limitnum == 0) or $forumsort == "") {
		$sql = "SELECT p.discussion, COUNT(p.id) AS replies, MAX(p.id) AS lastpostid
				  FROM {$CFG->prefix}forum_posts p
					   JOIN {$CFG->prefix}forum_discussions d ON p.discussion = d.id
				 WHERE p.parent > 0 AND d.forum = $forumid
			  GROUP BY p.discussion";
		return get_records_sql($sql);

	} else {
		$sql = "SELECT p.discussion, (COUNT(p.id) - 1) AS replies, MAX(p.id) AS lastpostid
				  FROM {$CFG->prefix}forum_posts p
					   JOIN {$CFG->prefix}forum_discussions d ON p.discussion = d.id
				 WHERE d.forum = $forumid
			  GROUP BY p.discussion $groupby
			  $orderby";
		return get_records_sql("SELECT * FROM ($sql) sq", $limitfrom, $limitnum);
	}
}

function forum_count_discussions($forum, $cm, $course) {
	global $CFG, $USER;

	static $cache = array();

	$now = round(time(), -2); // db cache friendliness

	if (!isset($cache[$course->id])) {
		if (!empty($CFG->forum_enabletimedposts)) {
			$timedsql = "AND d.timestart < $now AND (d.timeend = 0 OR d.timeend > $now)";
		} else {
			$timedsql = "";
		}

		$sql = "SELECT f.id, COUNT(d.id) as dcount
				  FROM {$CFG->prefix}forum f
					   JOIN {$CFG->prefix}forum_discussions d ON d.forum = f.id
				 WHERE f.course = $course->id
					   $timedsql
			  GROUP BY f.id";

		if ($counts = get_records_sql($sql)) {
			foreach ($counts as $count) {
				$counts[$count->id] = $count->dcount;
			}
			$cache[$course->id] = $counts;
		} else {
			$cache[$course->id] = array();
		}
	}

	if (empty($cache[$course->id][$forum->id])) {
		return 0;
	}

	$groupmode = groups_get_activity_groupmode($cm, $course);

	if ($groupmode != SEPARATEGROUPS) {
		return $cache[$course->id][$forum->id];
	}

	if (has_capability('moodle/site:accessallgroups', get_context_instance(CONTEXT_MODULE, $cm->id))) {
		return $cache[$course->id][$forum->id];
	}

	require_once($CFG->dirroot.'/course/lib.php');

	$modinfo =& get_fast_modinfo($course);
	if (is_null($modinfo->groups)) {
		$modinfo->groups = groups_get_user_groups($course->id, $USER->id);
	}

	if (empty($CFG->enablegroupings)) {
		$mygroups = $modinfo->groups[0];
	} else {
		$mygroups = $modinfo->groups[$cm->groupingid];
	}

	// add all groups posts
	if (empty($mygroups)) {
		$mygroups = array(-1=>-1);
	} else {
		$mygroups[-1] = -1;
	}
	$mygroups = implode(',', $mygroups);

	if (!empty($CFG->forum_enabletimedposts)) {
		$timedsql = "AND d.timestart < $now AND (d.timeend = 0 OR d.timeend > $now)";
	} else {
		$timedsql = "";
	}

	$sql = "SELECT COUNT(d.id)
			  FROM {$CFG->prefix}forum_discussions d
			 WHERE d.forum = $forum->id AND d.groupid IN ($mygroups)
				   $timedsql";

	return get_field_sql($sql);
}

/**
 * How many unrated posts are in the given discussion for a given user?
 */
function forum_count_unrated_posts($discussionid, $userid) {
	global $CFG;
	if ($posts = get_record_sql("SELECT count(*) as num
								   FROM {$CFG->prefix}forum_posts
								  WHERE parent > 0
									AND discussion = '$discussionid'
									AND userid <> '$userid' ")) {

		if ($rated = get_record_sql("SELECT count(*) as num
									   FROM {$CFG->prefix}forum_posts p,
											{$CFG->prefix}forum_ratings r
									  WHERE p.discussion = '$discussionid'
										AND p.id = r.post
										AND r.userid = '$userid'")) {
			$difference = $posts->num - $rated->num;
			if ($difference > 0) {
				return $difference;
			} else {
				return 0;	// Just in case there was a counting error
			}
		} else {
			return $posts->num;
		}
	} else {
		return 0;
	}
}

/**
 * Get all discussions in a forum
 */
function forum_get_discussions($cm, $forumsort="d.timemodified DESC", $fullpost=true, $unused=-1, $limit=-1, $userlastmodified=false, $page=-1, $perpage=0) {
	global $CFG, $USER;

	$timelimit = '';

	$modcontext = null;

	$now = round(time(), -2);

	$modcontext = get_context_instance(CONTEXT_MODULE, $cm->id);

	if (!has_capability('mod/forum:viewdiscussion', $modcontext)) { /// User must have perms to view discussions
		return array();
	}

	if (!empty($CFG->forum_enabletimedposts)) { /// Users must fulfill timed posts

		if (!has_capability('mod/forum:viewhiddentimedposts', $modcontext)) {
			$timelimit = " AND ((d.timestart <= $now AND (d.timeend = 0 OR d.timeend > $now))";
			if (isloggedin()) {
				$timelimit .= " OR d.userid = $USER->id";
			}
			$timelimit .= ")";
		}
	}

	if ($limit > 0) {
		$limitfrom = 0;
		$limitnum  = $limit;
	} else if ($page != -1) {
		$limitfrom = $page*$perpage;
		$limitnum  = $perpage;
	} else {
		$limitfrom = 0;
		$limitnum  = 0;
	}

	$groupmode	= groups_get_activity_groupmode($cm);
	$currentgroup = groups_get_activity_group($cm);

	if ($groupmode) {
		if (empty($modcontext)) {
			$modcontext = get_context_instance(CONTEXT_MODULE, $cm->id);
		}

		if ($groupmode == VISIBLEGROUPS or has_capability('moodle/site:accessallgroups', $modcontext)) {
			if ($currentgroup) {
				$groupselect = "AND (d.groupid = $currentgroup OR d.groupid = -1)";
			} else {
				$groupselect = "";
			}

		} else {
			//seprate groups without access all
			if ($currentgroup) {
				$groupselect = "AND (d.groupid = $currentgroup OR d.groupid = -1)";
			} else {
				$groupselect = "AND d.groupid = -1";
			}
		}
	} else {
		$groupselect = "";
	}


	if (empty($forumsort)) {
		$forumsort = "d.timemodified DESC";
	}
	if (empty($fullpost)) {
		$postdata = "p.id,p.subject,p.modified,p.discussion,p.userid";
	} else {
		$postdata = "p.*";
	}

	if (empty($userlastmodified)) {  // We don't need to know this
		$umfields = "";
		$umtable  = "";
	} else {
		$umfields = ", um.firstname AS umfirstname, um.lastname AS umlastname";
		$umtable  = " LEFT JOIN {$CFG->prefix}user um ON (d.usermodified = um.id)";
	}

	$sql = "SELECT $postdata, d.name, d.timemodified, d.usermodified, d.groupid, d.timestart, d.timeend,
				   u.firstname, u.lastname, u.email, u.picture, u.imagealt $umfields
			  FROM {$CFG->prefix}forum_discussions d
				   JOIN {$CFG->prefix}forum_posts p ON p.discussion = d.id
				   JOIN {$CFG->prefix}user u ON p.userid = u.id
				   $umtable
			 WHERE d.forum = {$cm->instance} AND p.parent = 0
				   $timelimit $groupselect
		  ORDER BY $forumsort";
	return get_records_sql($sql, $limitfrom, $limitnum);
}

function forum_get_discussions_unread($cm) {
	global $CFG, $USER;

	$now = round(time(), -2);

	$groupmode	= groups_get_activity_groupmode($cm);
	$currentgroup = groups_get_activity_group($cm);

	if ($groupmode) {
		$modcontext = get_context_instance(CONTEXT_MODULE, $cm->id);

		if ($groupmode == VISIBLEGROUPS or has_capability('moodle/site:accessallgroups', $modcontext)) {
			if ($currentgroup) {
				$groupselect = "AND (d.groupid = $currentgroup OR d.groupid = -1)";
			} else {
				$groupselect = "";
			}

		} else {
			//seprate groups without access all
			if ($currentgroup) {
				$groupselect = "AND (d.groupid = $currentgroup OR d.groupid = -1)";
			} else {
				$groupselect = "AND d.groupid = -1";
			}
		}
	} else {
		$groupselect = "";
	}

	$cutoffdate = $now - ($CFG->forum_oldpostdays*24*60*60);

	if (!empty($CFG->forum_enabletimedposts)) {
		$timedsql = "AND d.timestart < $now AND (d.timeend = 0 OR d.timeend > $now)";
	} else {
		$timedsql = "";
	}

	$sql = "SELECT d.id, COUNT(p.id) AS unread
			  FROM {$CFG->prefix}forum_discussions d
				   JOIN {$CFG->prefix}forum_posts p	 ON p.discussion = d.id
				   LEFT JOIN {$CFG->prefix}forum_read r ON (r.postid = p.id AND r.userid = $USER->id)
			 WHERE d.forum = {$cm->instance}
				   AND p.modified >= $cutoffdate AND r.id is NULL
				   $timedsql
				   $groupselect
		  GROUP BY d.id";
	if ($unreads = get_records_sql($sql)) {
		foreach ($unreads as $unread) {
			$unreads[$unread->id] = $unread->unread;
		}
		return $unreads;
	} else {
		return array();
	}
}

function forum_get_discussions_count($cm) {
	global $CFG, $USER;

	$now = round(time(), -2);

	$groupmode	= groups_get_activity_groupmode($cm);
	$currentgroup = groups_get_activity_group($cm);

	if ($groupmode) {
		$modcontext = get_context_instance(CONTEXT_MODULE, $cm->id);

		if ($groupmode == VISIBLEGROUPS or has_capability('moodle/site:accessallgroups', $modcontext)) {
			if ($currentgroup) {
				$groupselect = "AND (d.groupid = $currentgroup OR d.groupid = -1)";
			} else {
				$groupselect = "";
			}

		} else {
			//seprate groups without access all
			if ($currentgroup) {
				$groupselect = "AND (d.groupid = $currentgroup OR d.groupid = -1)";
			} else {
				$groupselect = "AND d.groupid = -1";
			}
		}
	} else {
		$groupselect = "";
	}

	$cutoffdate = $now - ($CFG->forum_oldpostdays*24*60*60);

	$timelimit = "";

	if (!empty($CFG->forum_enabletimedposts)) {

		$modcontext = get_context_instance(CONTEXT_MODULE, $cm->id);

		if (!has_capability('mod/forum:viewhiddentimedposts', $modcontext)) {
			$timelimit = " AND ((d.timestart <= $now AND (d.timeend = 0 OR d.timeend > $now))";
			if (isloggedin()) {
				$timelimit .= " OR d.userid = $USER->id";
			}
			$timelimit .= ")";
		}
	}

	$sql = "SELECT COUNT(d.id)
			  FROM {$CFG->prefix}forum_discussions d
				   JOIN {$CFG->prefix}forum_posts p ON p.discussion = d.id
			 WHERE d.forum = {$cm->instance} AND p.parent = 0
				   $timelimit $groupselect";

	return get_field_sql($sql);
}


/**
 * Get all discussions started by a particular user in a course (or group)
 * This function no longer used ...
 */
function forum_get_user_discussions($courseid, $userid, $groupid=0) {
	global $CFG;

	if ($groupid) {
		$groupselect = " AND d.groupid = '$groupid' ";
	} else  {
		$groupselect = "";
	}

	return get_records_sql("SELECT p.*, d.groupid, u.firstname, u.lastname, u.email, u.picture, u.imagealt,
								   f.type as forumtype, f.name as forumname, f.id as forumid
							  FROM {$CFG->prefix}forum_discussions d,
								   {$CFG->prefix}forum_posts p,
								   {$CFG->prefix}user u,
								   {$CFG->prefix}forum f
							 WHERE d.course = '$courseid'
							   AND p.discussion = d.id
							   AND p.parent = 0
							   AND p.userid = u.id
							   AND u.id = '$userid'
							   AND d.forum = f.id $groupselect
						  ORDER BY p.created DESC");
}

/**
 * Get the list of potential subscribers to a forum. 
 *
 * @param object $forumcontext the forum context.
 * @param integer $groupid the id of a group, or 0 for all groups.
 * @param string $fields the list of fields to return for each user. As for get_users_by_capability.
 * @param string $sort sort order. As for get_users_by_capability.
 * @return array list of users.
 */
function forum_get_potential_subscribers($forumcontext, $groupid, $fields, $sort) {
	return get_users_by_capability($forumcontext, 'mod/forum:initialsubscriptions', $fields, $sort, '', '', $groupid, '', false, true);
}

/**
 * Returns list of user objects that are subscribed to this forum
 *
 * @param object $course the course
 * @param forum $forum the forum
 * @param integer $groupid group id, or 0 for all.
 * @param object $context the forum context, to save re-fetching it where possible.
 * @return array list of users.
 */
function forum_subscribed_users($course, $forum, $groupid=0, $context = NULL) {
	global $CFG;

	if ($groupid) {
		$grouptables = ", {$CFG->prefix}groups_members gm ";
		$groupselect = "AND gm.groupid = $groupid AND u.id = gm.userid";

	} else  {
		$grouptables = '';
		$groupselect = '';
	}

	if (forum_is_forcesubscribed($forum)) {
		if (empty($context)) {
			$cm = get_coursemodule_from_instance('forum', $forum->id, $course->id);
			$context = get_context_instance(CONTEXT_MODULE, $cm->id);
		}
		$sort = "u.email ASC";
		$fields ="u.id, u.username, u.firstname, u.lastname, u.maildisplay, u.mailformat, u.maildigest, u.emailstop, u.imagealt,
				  u.email, u.city, u.country, u.lastaccess, u.lastlogin, u.picture, u.timezone, u.theme, u.lang, u.trackforums, u.mnethostid";
		$results = forum_get_potential_subscribers($context, $groupid, $fields, $sort);
	} else {
		$results = get_records_sql("SELECT u.id, u.username, u.firstname, u.lastname, u.maildisplay, u.mailformat, u.maildigest, u.emailstop, u.imagealt,
								   u.email, u.city, u.country, u.lastaccess, u.lastlogin, u.picture, u.timezone, u.theme, u.lang, u.trackforums, u.mnethostid
							  FROM {$CFG->prefix}user u,
								   {$CFG->prefix}forum_subscriptions s $grouptables
							 WHERE s.forum = '$forum->id'
							   AND s.userid = u.id
							   AND u.deleted = 0  $groupselect
						  ORDER BY u.email ASC");
	}

	static $guestid = null;

	if (is_null($guestid)) {
		if ($guest = guest_user()) {
			$guestid = $guest->id;
		} else {
			$guestid = 0;
		}
	}

	// Guest user should never be subscribed to a forum.
	unset($results[$guestid]);

	return $results;
}



// OTHER FUNCTIONS ///////////////////////////////////////////////////////////


function forum_get_course_forum($courseid, $type) {
// How to set up special 1-per-course forums
	global $CFG;

	if ($forums = get_records_select("forum", "course = '$courseid' AND type = '$type'", "id ASC")) {
		// There should always only be ONE, but with the right combination of
		// errors there might be more.  In this case, just return the oldest one (lowest ID).
		foreach ($forums as $forum) {
			return $forum;   // ie the first one
		}
	}

	// Doesn't exist, so create one now.
	$forum->course = $courseid;
	$forum->type = "$type";
	switch ($forum->type) {
		case "news":
			$forum->name  = addslashes(get_string("namenews", "forum"));
			$forum->intro = addslashes(get_string("intronews", "forum"));
			$forum->forcesubscribe = FORUM_FORCESUBSCRIBE;
			$forum->assessed = 0;
			if ($courseid == SITEID) {
				$forum->name  = get_string("sitenews");
				$forum->forcesubscribe = 0;
			}
			break;
		case "social":
			$forum->name  = addslashes(get_string("namesocial", "forum"));
			$forum->intro = addslashes(get_string("introsocial", "forum"));
			$forum->assessed = 0;
			$forum->forcesubscribe = 0;
			break;
		default:
			notify("That forum type doesn't exist!");
			return false;
			break;
	}

	$forum->timemodified = time();
	$forum->id = insert_record("forum", $forum);

	if (! $module = get_record("modules", "name", "forum")) {
		notify("Could not find forum module!!");
		return false;
	}
	$mod = new object();
	$mod->course = $courseid;
	$mod->module = $module->id;
	$mod->instance = $forum->id;
	$mod->section = 0;
	if (! $mod->coursemodule = add_course_module($mod) ) {   // assumes course/lib.php is loaded
		notify("Could not add a new course module to the course '" . format_string($course->fullname) . "'");
		return false;
	}
	if (! $sectionid = add_mod_to_section($mod) ) {   // assumes course/lib.php is loaded
		notify("Could not add the new course module to that section");
		return false;
	}
	if (! set_field("course_modules", "section", $sectionid, "id", $mod->coursemodule)) {
		notify("Could not update the course module with the correct section");
		return false;
	}
	include_once("$CFG->dirroot/course/lib.php");
	rebuild_course_cache($courseid);

	return get_record("forum", "id", "$forum->id");
}


/**
* Given the data about a posting, builds up the HTML to display it and
* returns the HTML in a string.  This is designed for sending via HTML email.
*/
function forum_make_mail_post($course, $forum, $discussion, $post, $userfrom, $userto,
							  $ownpost=false, $reply=false, $link=false, $rate=false, $footer="") {

	global $CFG;

	if (!isset($userto->viewfullnames[$forum->id])) {
		if (!$cm = get_coursemodule_from_instance('forum', $forum->id, $course->id)) {
			error('Course Module ID was incorrect');
		}
		$modcontext = get_context_instance(CONTEXT_MODULE, $cm->id);
		$viewfullnames = has_capability('moodle/site:viewfullnames', $modcontext, $userto->id);
	} else {
		$viewfullnames = $userto->viewfullnames[$forum->id];
	}

	// format the post body
	$options = new object();
	$options->para = true;
	$formattedtext = format_text(trusttext_strip($post->message), $post->format, $options, $course->id);

	$output = '<table border="0" cellpadding="3" cellspacing="0" class="forumpost">';

	$output .= '<tr class="header"><td width="35" valign="top" class="picture left">';
	$output .= print_user_picture($userfrom, $course->id, $userfrom->picture, false, true);
	$output .= '</td>';

	if ($post->parent) {
		$output .= '<td class="topic">';
	} else {
		$output .= '<td class="topic starter">';
	}
	$output .= '<div class="subject">'.format_string($post->subject).'</div>';

	$fullname = fullname($userfrom, $viewfullnames);
	$by = new object();
	$by->name = '<a href="'.$CFG->wwwroot.'/user/view.php?id='.$userfrom->id.'&amp;course='.$course->id.'">'.$fullname.'</a>';
	$by->date = userdate($post->modified, '', $userto->timezone);
	$output .= '<div class="author">'.get_string('bynameondate', 'forum', $by).'</div>';

	$output .= '</td></tr>';

	$output .= '<tr><td class="left side" valign="top">';

	if (isset($userfrom->groups)) {
		$groups = $userfrom->groups[$forum->id];
	} else {
		if (!$cm = get_coursemodule_from_instance('forum', $forum->id, $course->id)) {
			error('Course Module ID was incorrect');
		}
		$group = groups_get_all_groups($course->id, $userfrom->id, $cm->groupingid);
	}

	if ($groups) {
		$output .= print_group_picture($groups, $course->id, false, true, true);
	} else {
		$output .= '&nbsp;';
	}

	$output .= '</td><td class="content">';

	if ($post->attachment) {
		$post->course = $course->id;
		$output .= '<div class="attachments">';
		$output .= forum_print_attachments($post, 'html');
		$output .= "</div>";
	}

	$output .= $formattedtext;

// Commands
	$commands = array();

	if ($post->parent) {
		$commands[] = '<a target="_blank" href="'.$CFG->wwwroot.'/mod/forum/discuss.php?d='.
					  $post->discussion.'&amp;parent='.$post->parent.'">'.get_string('parent', 'forum').'</a>';
	}

	if ($reply) {
		$commands[] = '<a target="_blank" href="'.$CFG->wwwroot.'/mod/forum/post.php?reply='.$post->id.'">'.
					  get_string('reply', 'forum').'</a>';
	}

	$output .= '<div class="commands">';
	$output .= implode(' | ', $commands);
	$output .= '</div>';

// Context link to post if required
	if ($link) {
		$output .= '<div class="link">';
		$output .= '<a target="_blank" href="'.$CFG->wwwroot.'/mod/forum/discuss.php?d='.$post->discussion.'#p'.$post->id.'">'.
					 get_string('postincontext', 'forum').'</a>';
		$output .= '</div>';
	}

	if ($footer) {
		$output .= '<div class="footer">'.$footer.'</div>';
	}
	$output .= '</td></tr></table>'."\n\n";

	return $output;
}

/**
 * Print a forum post
 *
 * @param object $post The post to print.
 * @param integer $courseid The course this post belongs to.
 * @param boolean $ownpost Whether this post belongs to the current user.
 * @param boolean $reply Whether to print a 'reply' link at the bottom of the message.
 * @param boolean $link Just print a shortened version of the post as a link to the full post.
 * @param object $ratings -- I don't really know --
 * @param string $footer Extra stuff to print after the message.
 * @param string $highlight Space-separated list of terms to highlight.
 * @param int $post_read true, false or -99. If we already know whether this user
 *		  has read this post, pass that in, otherwise, pass in -99, and this
 *		  function will work it out.
 * @param boolean $dummyifcantsee When forum_user_can_see_post says that
 *		  the current user can't see this post, if this argument is true
 *		  (the default) then print a dummy 'you can't see this post' post.
 *		  If false, don't output anything at all.
 */
function forum_print_post($post, $discussion, $forum, &$cm, $course, $ownpost=false, $reply=false, $link=false,
						  $ratings=NULL, $footer="", $highlight="", $post_read=null, $dummyifcantsee=true, $istracked=null) {

	global $USER, $CFG;

	static $stredit, $strdelete, $strreply, $strparent, $strprune;
	static $strpruneheading, $displaymode;
	static $strmarkread, $strmarkunread;

	$post->course = $course->id;
	$post->forum  = $forum->id;

	// caching
	if (!isset($cm->cache)) {
		$cm->cache = new object();
	}

	if (!isset($cm->cache->caps)) {
		$cm->cache->caps = array();
		$modcontext = get_context_instance(CONTEXT_MODULE, $cm->id);
		$cm->cache->caps['mod/forum:viewdiscussion']   = has_capability('mod/forum:viewdiscussion', $modcontext);
		$cm->cache->caps['moodle/site:viewfullnames']  = has_capability('moodle/site:viewfullnames', $modcontext);
		$cm->cache->caps['mod/forum:editanypost']	  = has_capability('mod/forum:editanypost', $modcontext);
		$cm->cache->caps['mod/forum:splitdiscussions'] = has_capability('mod/forum:splitdiscussions', $modcontext);
		$cm->cache->caps['mod/forum:deleteownpost']	= has_capability('mod/forum:deleteownpost', $modcontext);
		$cm->cache->caps['mod/forum:deleteanypost']	= has_capability('mod/forum:deleteanypost', $modcontext);
		$cm->cache->caps['mod/forum:viewanyrating']	= has_capability('mod/forum:viewanyrating', $modcontext);
	}

	if (!isset($cm->uservisible)) {
		$cm->uservisible = coursemodule_visible_for_user($cm);
	}

	if (!forum_user_can_see_post($forum, $discussion, $post, NULL, $cm)) {
		if (!$dummyifcantsee) {
			return;
		}
		echo '<a id="p'.$post->id.'"></a>';
		echo '<table cellspacing="0" class="forumpost">';
		echo '<tr class="header"><td class="picture left">';
		//		print_user_picture($post->userid, $courseid, $post->picture);
		echo '</td>';
		if ($post->parent) {
			echo '<td class="topic">';
		} else {
			echo '<td class="topic starter">';
		}
		echo '<div class="subject">'.get_string('forumsubjecthidden','forum').'</div>';
		echo '<div class="author">';
		print_string('forumauthorhidden','forum');
		echo '</div></td></tr>';

		echo '<tr><td class="left side">';
		echo '&nbsp;';

		// Actual content

		echo '</td><td class="content">'."\n";
		echo get_string('forumbodyhidden','forum');
		echo '</td></tr></table>';
		return;
	}

	if (empty($stredit)) {
		$stredit		 = get_string('edit', 'forum');
		$strdelete	   = get_string('delete', 'forum');
		$strreply		= get_string('reply', 'forum');
		$strparent	   = get_string('parent', 'forum');
		$strpruneheading = get_string('pruneheading', 'forum');
		$strprune		= get_string('prune', 'forum');
		$displaymode	 = get_user_preferences('forum_displaymode', $CFG->forum_displaymode);
		$strmarkread	 = get_string('markread', 'forum');
		$strmarkunread   = get_string('markunread', 'forum');

	}

	$read_style = '';
	// ignore trackign status if not tracked or tracked param missing
	if ($istracked) {
		if (is_null($post_read)) {
			debugging('fetching post_read info');
			$post_read = forum_tp_is_post_read($USER->id, $post);
		}

		if ($post_read) {
			$read_style = ' read';
		} else {
			$read_style = ' unread';
			echo '<a name="unread"></a>';
		}
	}

	echo '<a id="p'.$post->id.'"></a>';
	echo '<table cellspacing="0" class="forumpost'.$read_style.'">';

	// Picture
	$postuser = new object();
	$postuser->id		= $post->userid;
	$postuser->firstname = $post->firstname;
	$postuser->lastname  = $post->lastname;
	$postuser->imagealt  = $post->imagealt;
	$postuser->picture   = $post->picture;

	echo '<tr class="header"><td class="picture left">';
	print_user_picture($postuser, $course->id);
	echo '</td>';

	if ($post->parent) {
		echo '<td class="topic">';
	} else {
		echo '<td class="topic starter">';
	}

	if (!empty($post->subjectnoformat)) {
		echo '<div class="subject">'.$post->subject.'</div>';
	} else {
		echo '<div class="subject">'.format_string($post->subject).'</div>';
	}

	echo '<div class="author">';
	$fullname = fullname($postuser, $cm->cache->caps['moodle/site:viewfullnames']);
	$by = new object();
	$by->name = '<a href="'.$CFG->wwwroot.'/user/view.php?id='.
				$post->userid.'&amp;course='.$course->id.'">'.$fullname.'</a>';
	$by->date = userdate($post->modified);
	print_string('bynameondate', 'forum', $by);
	echo '</div></td></tr>';

	echo '<tr><td class="left side">';
	if (isset($cm->cache->usersgroups)) {
		$groups = array();
		if (isset($cm->cache->usersgroups[$post->userid])) {
			foreach ($cm->cache->usersgroups[$post->userid] as $gid) {
				$groups[$gid] = $cm->cache->groups[$gid];
			}
		}
	} else {
		$groups = groups_get_all_groups($course->id, $post->userid, $cm->groupingid);
	}

	if ($groups) {
		print_group_picture($groups, $course->id, false, false, true);
	} else {
		echo '&nbsp;';
	}

// Actual content

	echo '</td><td class="content">'."\n";

	if ($post->attachment) {
		echo '<div class="attachments">';
		$attachedimages = forum_print_attachments($post);
		echo '</div>';
	} else {
		$attachedimages = '';
	}


	$options = new object();
	$options->para	  = false;
	$options->trusttext = true;
	if ($link and (strlen(strip_tags($post->message)) > $CFG->forum_longpost)) {
		// Print shortened version
		echo format_text(forum_shorten_post($post->message), $post->format, $options, $course->id);
		$numwords = count_words(strip_tags($post->message));
		echo '<div class="posting"><a href="'.$CFG->wwwroot.'/mod/forum/discuss.php?d='.$post->discussion.'">';
		echo get_string('readtherest', 'forum');
		echo '</a> ('.get_string('numwords', '', $numwords).')...</div>';
	} else {
		// Print whole message
		echo '<div class="posting">';
		if ($highlight) {
			echo highlight($highlight, format_text($post->message, $post->format, $options, $course->id));
		} else {
			echo format_text($post->message, $post->format, $options, $course->id);
		}
		echo '</div>';
		echo $attachedimages;
	}


// Commands

	$commands = array();

	if ($istracked) {
		// SPECIAL CASE: The front page can display a news item post to non-logged in users.
		// Don't display the mark read / unread controls in this case.
		if ($CFG->forum_usermarksread and isloggedin()) {
			if ($post_read) {
				$mcmd = '&amp;mark=unread&amp;postid='.$post->id;
				$mtxt = $strmarkunread;
			} else {
				$mcmd = '&amp;mark=read&amp;postid='.$post->id;
				$mtxt = $strmarkread;
			}
			if ($displaymode == FORUM_MODE_THREADED) {
				$commands[] = '<a href="'.$CFG->wwwroot.'/mod/forum/discuss.php?d='.
							  $post->discussion.'&amp;parent='.$post->id.$mcmd.'">'.$mtxt.'</a>';
			} else {
				$commands[] = '<a href="'.$CFG->wwwroot.'/mod/forum/discuss.php?d='.
							  $post->discussion.$mcmd.'#p'.$post->id.'">'.$mtxt.'</a>';
			}
		}
	}

	if ($post->parent) {  // Zoom in to the parent specifically
		if ($displaymode == FORUM_MODE_THREADED) {
			$commands[] = '<a href="'.$CFG->wwwroot.'/mod/forum/discuss.php?d='.
					  $post->discussion.'&amp;parent='.$post->parent.'">'.$strparent.'</a>';
		} else {
			$commands[] = '<a href="'.$CFG->wwwroot.'/mod/forum/discuss.php?d='.
					  $post->discussion.'#p'.$post->parent.'">'.$strparent.'</a>';
		}
	}

	$age = time() - $post->created;
	// Hack for allow to edit news posts those are not displayed yet until they are displayed
	if (!$post->parent and $forum->type == 'news' and $discussion->timestart > time()) {
		$age = 0;
	}
	$editanypost = $cm->cache->caps['mod/forum:editanypost'];

	if ($ownpost or $editanypost) {
		if (($age < $CFG->maxeditingtime) or $editanypost) {
			$commands[] =  '<a href="'.$CFG->wwwroot.'/mod/forum/post.php?edit='.$post->id.'">'.$stredit.'</a>';
		}
	}

	if ($cm->cache->caps['mod/forum:splitdiscussions']
				&& $post->parent && $forum->type != 'single') {

		$commands[] = '<a href="'.$CFG->wwwroot.'/mod/forum/post.php?prune='.$post->id.
					  '" title="'.$strpruneheading.'">'.$strprune.'</a>';
	}

	if (($ownpost and $age < $CFG->maxeditingtime
				and $cm->cache->caps['mod/forum:deleteownpost'])
				or $cm->cache->caps['mod/forum:deleteanypost']) {
		$commands[] = '<a href="'.$CFG->wwwroot.'/mod/forum/post.php?delete='.$post->id.'">'.$strdelete.'</a>';
	}

	if ($reply) {
		$commands[] = '<a href="'.$CFG->wwwroot.'/mod/forum/post.php?reply='.$post->id.'">'.$strreply.'</a>';
	}

	echo '<div class="commands">';
	echo implode(' | ', $commands);
	echo '</div>';


// Ratings

	$ratingsmenuused = false;
	if (!empty($ratings) and isloggedin()) {
		echo '<div class="ratings">';
		$useratings = true;
		if ($ratings->assesstimestart and $ratings->assesstimefinish) {
			if ($post->created < $ratings->assesstimestart or $post->created > $ratings->assesstimefinish) {
				$useratings = false;
			}
		}
		if ($useratings) {
			$mypost = ($USER->id == $post->userid);

			$canviewallratings = $cm->cache->caps['mod/forum:viewanyrating'];

			if (isset($cm->cache->ratings)) {
				if (isset($cm->cache->ratings[$post->id])) {
					$allratings = $cm->cache->ratings[$post->id];
				} else {
					$allratings = array(); // no reatings present yet
				}
			} else {
				$allratings = NULL; // not preloaded
			}

			if (isset($cm->cache->myratings)) {
				if (isset($cm->cache->myratings[$post->id])) {
					$myrating = $cm->cache->myratings[$post->id];
				} else {
					$myrating = FORUM_UNSET_POST_RATING; // no reatings present yet
				}
			} else {
				$myrating = NULL; // not preloaded
			}

			if ($canviewallratings and !$mypost) {
				echo '<span class="forumpostratingtext">' .
					 forum_print_ratings($post->id, $ratings->scale, $forum->assessed, $canviewallratings, $allratings, true) .
					 '</span>';
				if (!empty($ratings->allow)) {
					echo '&nbsp;';
					forum_print_rating_menu($post->id, $USER->id, $ratings->scale, $myrating);
					$ratingsmenuused = true;
				}

			} else if ($mypost) {
				echo '<span class="forumpostratingtext">' .
					 forum_print_ratings($post->id, $ratings->scale, $forum->assessed, true, $allratings, true) .
					 '</span>';

			} else if (!empty($ratings->allow) ) {
				forum_print_rating_menu($post->id, $USER->id, $ratings->scale, $myrating);
				$ratingsmenuused = true;
			}
		}
		echo '</div>';
	}

// Link to post if required

	if ($link) {
		echo '<div class="link">';
		if ($post->replies == 1) {
			$replystring = get_string('repliesone', 'forum', $post->replies);
		} else {
			$replystring = get_string('repliesmany', 'forum', $post->replies);
		}
		echo '<a href="'.$CFG->wwwroot.'/mod/forum/discuss.php?d='.$post->discussion.'">'.
			 get_string('discussthistopic', 'forum').'</a>&nbsp;('.$replystring.')';
		echo '</div>';
	}

	if ($footer) {
		echo '<div class="footer">'.$footer.'</div>';
	}
	echo '</td></tr></table>'."\n\n";

	if ($istracked && !$CFG->forum_usermarksread && !$post_read) {
		forum_tp_mark_post_read($USER->id, $post, $forum->id);
	}

	return $ratingsmenuused;
}


/**
 * This function prints the overview of a discussion in the forum listing.
 * It needs some discussion information and some post information, these
 * happen to be combined for efficiency in the $post parameter by the function
 * that calls this one: forum_print_latest_discussions()
 *
 * @param object $post The post object (passed by reference for speed).
 * @param object $forum The forum object.
 * @param int $group Current group.
 * @param string $datestring Format to use for the dates.
 * @param boolean $cantrack Is tracking enabled for this forum.
 * @param boolean $forumtracked Is the user tracking this forum.
 * @param boolean $canviewparticipants True if user has the viewparticipants permission for this course
 */
function forum_print_discussion_header(&$post, $forum, $group=-1, $datestring="",
										$cantrack=true, $forumtracked=true, $canviewparticipants=true, $modcontext=NULL) {

	global $USER, $CFG;

	static $rowcount;
	static $strmarkalldread;

	if (empty($modcontext)) {
		if (!$cm = get_coursemodule_from_instance('forum', $forum->id, $forum->course)) {
			error('Course Module ID was incorrect');
		}
		$modcontext = get_context_instance(CONTEXT_MODULE, $cm->id);
	}

	if (!isset($rowcount)) {
		$rowcount = 0;
		$strmarkalldread = get_string('markalldread', 'forum');
	} else {
		$rowcount = ($rowcount + 1) % 2;
	}

	$post->subject = format_string($post->subject,true);

	echo "\n\n";
	echo '<tr class="discussion r'.$rowcount.'">';

	// Topic
	echo '<td class="topic starter">';
	echo '<a href="'.$CFG->wwwroot.'/mod/forum/discuss.php?d='.$post->discussion.'">'.$post->subject.'</a>';
	echo "</td>\n";

	// Picture
	$postuser = new object;
	$postuser->id = $post->userid;
	$postuser->firstname = $post->firstname;
	$postuser->lastname = $post->lastname;
	$postuser->imagealt = $post->imagealt;
	$postuser->picture = $post->picture;

	echo '<td class="picture">';
	print_user_picture($postuser, $forum->course);
	echo "</td>\n";

	// User name
	$fullname = fullname($post, has_capability('moodle/site:viewfullnames', $modcontext));
	echo '<td class="author">';
	echo '<a href="'.$CFG->wwwroot.'/user/view.php?id='.$post->userid.'&amp;course='.$forum->course.'">'.$fullname.'</a>';
	echo "</td>\n";

	// Group picture
	if ($group !== -1) {  // Groups are active - group is a group data object or NULL
		echo '<td class="picture group">';
		if (!empty($group->picture) and empty($group->hidepicture)) {
			print_group_picture($group, $forum->course, false, false, true);
		} else if (isset($group->id)) {
			if($canviewparticipants) {
				echo '<a href="'.$CFG->wwwroot.'/user/index.php?id='.$forum->course.'&amp;group='.$group->id.'">'.$group->name.'</a>';
			} else {
				echo $group->name;
			}
		}
		echo "</td>\n";
	}

	if (has_capability('mod/forum:viewdiscussion', $modcontext)) {   // Show the column with replies
		echo '<td class="replies">';
		echo '<a href="'.$CFG->wwwroot.'/mod/forum/discuss.php?d='.$post->discussion.'">';
		echo $post->replies.'</a>';
		echo "</td>\n";

		if ($cantrack) {
			echo '<td class="replies">';
			if ($forumtracked) {
				if ($post->unread > 0) {
					echo '<span class="unread">';
					echo '<a href="'.$CFG->wwwroot.'/mod/forum/discuss.php?d='.$post->discussion.'#unread">';
					echo $post->unread;
					echo '</a>';
					echo '<a title="'.$strmarkalldread.'" href="'.$CFG->wwwroot.'/mod/forum/markposts.php?f='.
						 $forum->id.'&amp;d='.$post->discussion.'&amp;mark=read&amp;returnpage=view.php">' .
						 '<img src="'.$CFG->pixpath.'/t/clear.gif" class="iconsmall" alt="'.$strmarkalldread.'" /></a>';
					echo '</span>';
				} else {
					echo '<span class="read">';
					echo $post->unread;
					echo '</span>';
				}
			} else {
				echo '<span class="read">';
				echo '-';
				echo '</span>';
			}
			echo "</td>\n";
		}
	}

	echo '<td class="lastpost">';
	$usedate = (empty($post->timemodified)) ? $post->modified : $post->timemodified;  // Just in case
	$parenturl = (empty($post->lastpostid)) ? '' : '&amp;parent='.$post->lastpostid;
	$usermodified = new object();
	$usermodified->id		= $post->usermodified;
	$usermodified->firstname = $post->umfirstname;
	$usermodified->lastname  = $post->umlastname;
	echo '<a href="'.$CFG->wwwroot.'/user/view.php?id='.$post->usermodified.'&amp;course='.$forum->course.'">'.
		 fullname($usermodified).'</a><br />';
	echo '<a href="'.$CFG->wwwroot.'/mod/forum/discuss.php?d='.$post->discussion.$parenturl.'">'.
		  userdate($usedate, $datestring).'</a>';
	echo "</td>\n";

	echo "</tr>\n\n";

}


/**
 * Given a post object that we already know has a long message
 * this function truncates the message nicely to the first
 * sane place between $CFG->forum_longpost and $CFG->forum_shortpost
 */
function forum_shorten_post($message) {

   global $CFG;

   $i = 0;
   $tag = false;
   $length = strlen($message);
   $count = 0;
   $stopzone = false;
   $truncate = 0;

   for ($i=0; $i<$length; $i++) {
	   $char = $message[$i];

	   switch ($char) {
		   case "<":
			   $tag = true;
			   break;
		   case ">":
			   $tag = false;
			   break;
		   default:
			   if (!$tag) {
				   if ($stopzone) {
					   if ($char == ".") {
						   $truncate = $i+1;
						   break 2;
					   }
				   }
				   $count++;
			   }
			   break;
	   }
	   if (!$stopzone) {
		   if ($count > $CFG->forum_shortpost) {
			   $stopzone = true;
		   }
	   }
   }

   if (!$truncate) {
	   $truncate = $i;
   }

   return substr($message, 0, $truncate);
}


/**
 * Print the multiple ratings on a post given to the current user by others.
 * Forumid prevents the double lookup of the forumid in discussion to determine the aggregate type
 * Scale is an array of ratings
 */
function forum_print_ratings($postid, $scale, $aggregatetype, $link=true, $ratings=null, $return=false) {

	$strratings = '';

	switch ($aggregatetype) {
		case FORUM_AGGREGATE_AVG :
			$agg		= forum_get_ratings_mean($postid, $scale, $ratings);
			$strratings = get_string("aggregateavg", "forum");
			break;
		case FORUM_AGGREGATE_COUNT :
			$agg		= forum_get_ratings_count($postid, $scale, $ratings);
			$strratings = get_string("aggregatecount", "forum");
			break;
		case FORUM_AGGREGATE_MAX :
			$agg		= forum_get_ratings_max($postid, $scale, $ratings);
			$strratings = get_string("aggregatemax", "forum");
			break;
		case FORUM_AGGREGATE_MIN :
			$agg		= forum_get_ratings_min($postid, $scale, $ratings);
			$strratings = get_string("aggregatemin", "forum");
			break;
		case FORUM_AGGREGATE_SUM :
			$agg		= forum_get_ratings_sum($postid, $scale, $ratings);
			$strratings = get_string("aggregatesum", "forum");
			break;
	}

	if ($agg !== "") {

		if (empty($strratings)) {
			$strratings = get_string("ratings", "forum");
		}

		$strratings .= ': ';

		if ($link) {
			$strratings .= link_to_popup_window ("/mod/forum/report.php?id=$postid", "ratings", $agg, 400, 600, null, null, true);
		} else {
			$strratings .= "$agg ";
		}

		if ($return) {
			return $strratings;
		} else {
			echo $strratings;
		}
	}
}


/**
 * Return the mean rating of a post given to the current user by others.
 * Scale is an array of possible ratings in the scale
 * Ratings is an optional simple array of actual ratings (just integers)
 * Forumid is the forum id field needed - passing it avoids a double query of lookup up the discusion and then the forum id to get the aggregate type
 */
function forum_get_ratings_mean($postid, $scale, $ratings=NULL) {

	if (is_null($ratings)) {
		$ratings = array();
		if ($rates = get_records("forum_ratings", "post", $postid)) {
			foreach ($rates as $rate) {
				$ratings[] = $rate->rating;
			}
		}
	}

	$count = count($ratings);

	if ($count == 0 ) {
		return "";

	} else if ($count == 1) {
		$rating = reset($ratings);
		return $scale[$rating];

	} else {
		$total = 0;
		foreach ($ratings as $rating) {
			$total += $rating;
		}
		$mean = round( ((float)$total/(float)$count) + 0.001);  // Little fudge factor so that 0.5 goes UP

		if (isset($scale[$mean])) {
			return $scale[$mean]." ($count)";
		} else {
			return "$mean ($count)";	// Should never happen, hopefully
		}
	}
}

/**
 * Return the count of the ratings of a post given to the current user by others.
 *
 * For numerical grades, the scale index is the same as the real grade value from interval {0..n}
 * and $scale looks like Array( 0 => '0/n', 1 => '1/n', ..., n => 'n/n' )
 *
 * For scales, the index is the order of the scale item {1..n}
 * and $scale looks like Array( 1 => 'poor', 2 => 'weak', 3 => 'good' )
 * In case of no ratings done yet, we have nothing to display.
 *
 * @param int $postid
 * @param array $scale Possible ratings in the scale - the end of the scale is the highest or max grade
 * @param array $ratings An optional simple array of actual ratings (just integers)
 */
function forum_get_ratings_count($postid, $scale, $ratings=NULL) {

	if (is_null($ratings)) {
		$ratings = array();
		if ($rates = get_records("forum_ratings", "post", $postid)) {
			foreach ($rates as $rate) {
				$ratings[] = $rate->rating;
			}
		}
	}

	$count = count($ratings);
	$maxgradeidx = max(array_keys($scale)); // For numerical grades, the index is the same as the real grade value {0..n}
											// and $scale looks like Array( 0 => '0/n', 1 => '1/n', ..., n => 'n/n' )
											// For scales, the index is the order of the scale item {1..n}
											// and $scale looks like Array( 1 => 'poor', 2 => 'weak', 3 => 'good' )
	if (! array_key_exists(0, $scale)) {
		$scaleused = true;
	} else {
		$scaleused = false;
	}

	if (($count == 0) && ($scaleused)) {	// If no rating given yet and we use a scale
		return get_string('noratinggiven', 'forum');
	} elseif ($count > $maxgradeidx) {	  // The count exceeds the max grade
		$a = new stdClass();
		$a->count = $count;
		$a->grade = $scale[$maxgradeidx];
		return get_string('aggregatecountformat', 'forum', $a);
	} else {								// Display the count and the aggregated grade for this post
		$a = new stdClass();
		$a->count = $count;
		$a->grade = $scale[$count];
		return get_string('aggregatecountformat', 'forum', $a);
	}
}

/**
 * Return the max rating of a post given to the current user by others.
 * Scale is an array of possible ratings in the scale
 * Ratings is an optional simple array of actual ratings (just integers)
 */
function forum_get_ratings_max($postid, $scale, $ratings=NULL) {

	if (is_null($ratings)) {
		$ratings = array();
		if ($rates = get_records("forum_ratings", "post", $postid)) {
			foreach ($rates as $rate) {
				$ratings[] = $rate->rating;
			}
		}
	}

	$count = count($ratings);
	$max = max($ratings);

	if ($count == 0 ) {
		return "";

	} else if ($count == 1) { //this works for max
		$rating = reset($ratings);
		return $scale[$rating];

	} else {

	 if (isset($scale[$max])) {
			return $scale[$max]." ($count)";
		} else {
			return "$max ($count)";	// Should never happen, hopefully
		}
	}
}

/**
 * Return the min rating of a post given to the current user by others.
 * Scale is an array of possible ratings in the scale
 * Ratings is an optional simple array of actual ratings (just integers)
 */
function forum_get_ratings_min($postid, $scale,  $ratings=NULL) {

	if (is_null($ratings)) {
		$ratings = array();
		if ($rates = get_records("forum_ratings", "post", $postid)) {
			foreach ($rates as $rate) {
				$ratings[] = $rate->rating;
			}
		}
	}

	$count = count($ratings);
	$min = min($ratings);

	if ($count == 0 ) {
		return "";

	} else if ($count == 1) {
		$rating = reset($ratings);
		return $scale[$rating]; //this works for min

	} else {

		if (isset($scale[$min])) {
			return $scale[$min]." ($count)";
		} else {
			return "$min ($count)";	// Should never happen, hopefully
		}
	}
}


/**
 * Return the sum or total of ratings of a post given to the current user by others.
 * Scale is an array of possible ratings in the scale
 * Ratings is an optional simple array of actual ratings (just integers)
 */
function forum_get_ratings_sum($postid, $scale, $ratings=NULL) {

	if (is_null($ratings)) {
		$ratings = array();
		if ($rates = get_records("forum_ratings", "post", $postid)) {
			foreach ($rates as $rate) {
				$ratings[] = $rate->rating;
			}
		}
	}

	$count = count($ratings);
	$scalecount = count($scale)-1; //this should give us the last element of the scale aka the max grade with  $scale[$scalecount]

	if ($count == 0 ) {
		return "";

	} else if ($count == 1) { //this works for max.
		$rating = reset($ratings);
		return $scale[$rating];

	} else {
		$total = 0;
		foreach ($ratings as $rating) {
			$total += $rating;
		}
		if ($total > $scale[$scalecount]) { //if the total exceeds the max grade then set it to the max grade
			$total = $scale[$scalecount];
		}
		if (isset($scale[$total])) {
			return $scale[$total]." ($count)";
		} else {
			return "$total ($count)";	// Should never happen, hopefully
		}
	}
}

/**
 * Return a summary of post ratings given to the current user by others.
 * Scale is an array of possible ratings in the scale
 * Ratings is an optional simple array of actual ratings (just integers)
 */
function forum_get_ratings_summary($postid, $scale, $ratings=NULL) {

	if (is_null($ratings)) {
		$ratings = array();
		if ($rates = get_records("forum_ratings", "post", $postid)) {
			foreach ($rates as $rate) {
				$rating[] = $rate->rating;
			}
		}
	}


	if (!$count = count($ratings)) {
		return "";
	}


	foreach ($scale as $key => $scaleitem) {
		$sumrating[$key] = 0;
	}

	foreach ($ratings as $rating) {
		$sumrating[$rating]++;
	}

	$summary = "";
	foreach ($scale as $key => $scaleitem) {
		$summary = $sumrating[$key].$summary;
		if ($key > 1) {
			$summary = "/$summary";
		}
	}
	return $summary;
}

/**
 * Print the menu of ratings as part of a larger form.
 * If the post has already been - set that value.
 * Scale is an array of ratings
 */
function forum_print_rating_menu($postid, $userid, $scale, $myrating=NULL) {

	static $strrate;

	if (is_null($myrating)) {
		if (!$rating = get_record("forum_ratings", "userid", $userid, "post", $postid)) {
			$myrating = FORUM_UNSET_POST_RATING;
		} else {
			$myrating = $rating->rating;
		}
	}

	if (empty($strrate)) {
		$strrate = get_string("rate", "forum");
	}
	$scale = array(FORUM_UNSET_POST_RATING => $strrate.'...') + $scale;
	choose_from_menu($scale, $postid, $myrating, '', '', '0', false, false, 0, '', false, false, 'forumpostratingmenu');
}

/**
 * Print the drop down that allows the user to select how they want to have
 * the discussion displayed.
 * @param $id - forum id if $forumtype is 'single',
 *			  discussion id for any other forum type
 * @param $mode - forum layout mode
 * @param $forumtype - optional
 */
function forum_print_mode_form($id, $mode, $forumtype='') {
	if ($forumtype == 'single') {
		echo '<div class="forummode">';
		popup_form("view.php?f=$id&amp;mode=", forum_get_layout_modes(), "mode", $mode, "");
		echo '</div>';
	} else {
		popup_form("discuss.php?d=$id&amp;mode=", forum_get_layout_modes(), "mode", $mode, "");
	}
}

/**
 *
 */
function forum_search_form($course, $search='') {
	global $CFG;

	$output  = '<div class="forumsearch">';
	$output .= '<form action="'.$CFG->wwwroot.'/mod/forum/search.php" style="display:inline">';
	$output .= '<fieldset class="invisiblefieldset">';
	$output .= helpbutton('search', get_string('search'), 'moodle', true, false, '', true);
	$output .= '<input name="search" type="text" size="18" value="'.s($search, true).'" alt="search" />';
	$output .= '<input value="'.get_string('searchforums', 'forum').'" type="submit" />';
	$output .= '<input name="id" type="hidden" value="'.$course->id.'" />';
	$output .= '</fieldset>';
	$output .= '</form>';
	$output .= '</div>';

	return $output;
}


/**
 *
 */
function forum_set_return() {
	global $CFG, $SESSION;

	if (! isset($SESSION->fromdiscussion)) {
		if (!empty($_SERVER['HTTP_REFERER'])) {
			$referer = $_SERVER['HTTP_REFERER'];
		} else {
			$referer = "";
		}
		// If the referer is NOT a login screen then save it.
		if (! strncasecmp("$CFG->wwwroot/login", $referer, 300)) {
			$SESSION->fromdiscussion = $_SERVER["HTTP_REFERER"];
		}
	}
}


/**
 *
 */
function forum_go_back_to($default) {
	global $SESSION;

	if (!empty($SESSION->fromdiscussion)) {
		$returnto = $SESSION->fromdiscussion;
		unset($SESSION->fromdiscussion);
		return $returnto;
	} else {
		return $default;
	}
}

/**
 * Creates a directory file name, suitable for make_upload_directory()
 */
function forum_file_area_name($post) {
	global $CFG;

	if (!isset($post->forum) or !isset($post->course)) {
		debugging('missing forum or course', DEBUG_DEVELOPER);
		if (!$discussion = get_record('forum_discussions', 'id', $post->discussion)) {
			return false;
		}
		if (!$forum = get_record('forum', 'id', $discussion->forum)) {
			return false;
		}
		$forumid  = $forum->id;
		$courseid = $forum->course;
	} else {
		$forumid  = $post->forum;
		$courseid = $post->course;
	}

	return "$courseid/$CFG->moddata/forum/$forumid/$post->id";
}

/**
 *
 */
function forum_file_area($post) {
	return make_upload_directory( forum_file_area_name($post) );
}

/**
 *
 */
function forum_delete_old_attachments($post, $exception="") {

/**
 * Deletes all the user files in the attachments area for a post
 * EXCEPT for any file named $exception
 */
	if ($basedir = forum_file_area($post)) {
		if ($files = get_directory_list($basedir)) {
			foreach ($files as $file) {
				if ($file != $exception) {
					unlink("$basedir/$file");
					notify("Existing file '$file' has been deleted!");
				}
			}
		}
		if (!$exception) {  // Delete directory as well, if empty
			rmdir("$basedir");
		}
	}
}

/**
 * Given a discussion object that is being moved to forumid,
 * this function checks all posts in that discussion
 * for attachments, and if any are found, these are
 * moved to the new forum directory.
 */
function forum_move_attachments($discussion, $forumid) {

	global $CFG;

	require_once($CFG->dirroot.'/lib/uploadlib.php');

	$return = true;

	if ($posts = get_records_select("forum_posts", "discussion = '$discussion->id' AND attachment <> ''")) {
		foreach ($posts as $oldpost) {
			$oldpost->course = $discussion->course;
			$oldpost->forum = $discussion->forum;
			$oldpostdir = "$CFG->dataroot/".forum_file_area_name($oldpost);
			if (is_dir($oldpostdir)) {
				$newpost = $oldpost;
				$newpost->forum = $forumid;
				$newpostdir = forum_file_area_name($newpost);
				// take off the last directory because otherwise we're renaming to a directory that already exists
				// and this is unhappy in certain situations, eg over an nfs mount and potentially on windows too.
				make_upload_directory(substr($newpostdir,0,strrpos($newpostdir,'/')));
				$newpostdir = $CFG->dataroot.'/'.forum_file_area_name($newpost);
				$files = get_directory_list($oldpostdir); // get it before we rename it.
				if (! @rename($oldpostdir, $newpostdir)) {
					$return = false;
				}
				foreach ($files as $file) {
					clam_change_log($oldpostdir.'/'.$file,$newpostdir.'/'.$file);
				}
			}
		}
	}
	return $return;
}

/**
 * if return=html, then return a html string.
 * if return=text, then return a text-only string.
 * otherwise, print HTML for non-images, and return image HTML
 */
function forum_print_attachments($post, $return=NULL) {

	global $CFG;

	$filearea = forum_file_area_name($post);

	$imagereturn = "";
	$output = "";

	if ($basedir = forum_file_area($post)) {
		if ($files = get_directory_list($basedir)) {
			$strattachment = get_string("attachment", "forum");
			foreach ($files as $file) {
				$icon = mimeinfo("icon", $file);
				$type = mimeinfo("type", $file);
				$ffurl = get_file_url("$filearea/$file");
				$image = "<img src=\"$CFG->pixpath/f/$icon\" class=\"icon\" alt=\"\" />";

				if ($return == "html") {
					$output .= "<a href=\"$ffurl\">$image</a> ";
					$output .= "<a href=\"$ffurl\">$file</a><br />";

				} else if ($return == "text") {
					$output .= "$strattachment $file:\n$ffurl\n";

				} else {
					if (in_array($type, array('image/gif', 'image/jpeg', 'image/png'))) {	// Image attachments don't get printed as links
						$imagereturn .= "<br /><img src=\"$ffurl\" alt=\"\" />";
					} else {
						echo "<a href=\"$ffurl\">$image</a> ";
						echo filter_text("<a href=\"$ffurl\">$file</a><br />");
					}
				}
			}
		}
	}

	if ($return) {
		return $output;
	}

	return $imagereturn;
}
/**
 * If successful, this function returns the name of the file
 * @param $post is a full post record, including course and forum
 * @param $newfile is a full upload array from $_FILES
 * @param $message is a string to hold the messages.
 */

/**
 *
 */
function forum_add_attachment($post, $inputname,&$message) {

	global $CFG;

	if (!$forum = get_record("forum", "id", $post->forum)) {
		return "";
	}

	if (!$course = get_record("course", "id", $forum->course)) {
		return "";
	}

	require_once($CFG->dirroot.'/lib/uploadlib.php');
	$um = new upload_manager($inputname,true,false,$course,false,$forum->maxbytes,true,true);
	$dir = forum_file_area_name($post);
	if ($um->process_file_uploads($dir)) {
		$message .= $um->get_errors();
		return $um->get_new_filename();
	}
	$message .= $um->get_errors();
	return null;
}

/**
 *
 */
function forum_add_new_post($post,&$message) {

	global $USER, $CFG;

	$discussion = get_record('forum_discussions', 'id', $post->discussion);
	$forum	  = get_record('forum', 'id', $discussion->forum);

	$post->created	= $post->modified = time();
	$post->mailed	 = "0";
	$post->userid	 = $USER->id;
	$post->attachment = "";
	$post->forum	  = $forum->id;	 // speedup
	$post->course	 = $forum->course; // speedup

	if (! $post->id = insert_record("forum_posts", $post)) {
		return false;
	}

	if ($post->attachment = forum_add_attachment($post, 'attachment',$message)) {
		set_field("forum_posts", "attachment", $post->attachment, "id", $post->id);
	}

	// Update discussion modified date
	set_field("forum_discussions", "timemodified", $post->modified, "id", $post->discussion);
	set_field("forum_discussions", "usermodified", $post->userid, "id", $post->discussion);

	if (forum_tp_can_track_forums($forum) && forum_tp_is_tracked($forum)) {
		forum_tp_mark_post_read($post->userid, $post, $post->forum);
	}

	return $post->id;
}

/**
 *
 */
function forum_update_post($post,&$message) {

	global $USER, $CFG;

	$forum = get_record('forum', 'id', $post->forum);

	$post->modified = time();

	$updatediscussion = new object();
	$updatediscussion->id		   = $post->discussion;
	$updatediscussion->timemodified = $post->modified; // last modified tracking
	$updatediscussion->usermodified = $post->userid;   // last modified tracking

	if (!$post->parent) {   // Post is a discussion starter - update discussion title and times too
		$updatediscussion->name	  = $post->subject;
		$updatediscussion->timestart = $post->timestart;
		$updatediscussion->timeend   = $post->timeend;
	}

	if (!update_record('forum_discussions', $updatediscussion)) {
		return false;
	}

	if ($newfilename = forum_add_attachment($post, 'attachment',$message)) {
		$post->attachment = $newfilename;
	} else {
		unset($post->attachment);
	}

	if (forum_tp_can_track_forums($forum) && forum_tp_is_tracked($forum)) {
		forum_tp_mark_post_read($post->userid, $post, $post->forum);
	}

	return update_record('forum_posts', $post);
}

/**
 * Given an object containing all the necessary data,
 * create a new discussion and return the id
 */
function forum_add_discussion($discussion,&$message) {

	global $USER, $CFG;

	$timenow = time();

	// The first post is stored as a real post, and linked
	// to from the discuss entry.

	$forum = get_record('forum', 'id', $discussion->forum);

	$post = new object();
	$post->discussion  = 0;
	$post->parent	  = 0;
	$post->userid	  = $USER->id;
	$post->created	 = $timenow;
	$post->modified	= $timenow;
	$post->mailed	  = 0;
	$post->subject	 = $discussion->name;
	$post->message	 = $discussion->intro;
	$post->attachment  = "";
	$post->forum	   = $forum->id;	 // speedup
	$post->course	  = $forum->course; // speedup
	$post->format	  = $discussion->format;
	$post->mailnow	 = $discussion->mailnow;

	if (! $post->id = insert_record("forum_posts", $post) ) {
		return 0;
	}

	if ($post->attachment = forum_add_attachment($post, 'attachment',$message)) {
		set_field("forum_posts", "attachment", $post->attachment, "id", $post->id); //ignore errors
	}

	// Now do the main entry for the discussion,
	// linking to this first post

	$discussion->firstpost	= $post->id;
	$discussion->timemodified = $timenow;
	$discussion->usermodified = $post->userid;
	$discussion->userid = $USER->id;

	if (! $post->discussion = insert_record("forum_discussions", $discussion) ) {
		delete_records("forum_posts", "id", $post->id);
		return 0;
	}

	// Finally, set the pointer on the post.
	if (! set_field("forum_posts", "discussion", $post->discussion, "id", $post->id)) {
		delete_records("forum_posts", "id", $post->id);
		delete_records("forum_discussions", "id", $post->discussion);
		return 0;
	}

	if (forum_tp_can_track_forums($forum) && forum_tp_is_tracked($forum)) {
		forum_tp_mark_post_read($post->userid, $post, $post->forum);
	}

	return $post->discussion;
}


/**
 *
 */
function forum_delete_discussion($discussion, $fulldelete=false) {
// $discussion is a discussion record object

	$result = true;

	if ($posts = get_records("forum_posts", "discussion", $discussion->id)) {
		foreach ($posts as $post) {
			$post->course = $discussion->course;
			$post->forum  = $discussion->forum;
			if (! delete_records("forum_ratings", "post", "$post->id")) {
				$result = false;
			}
			if (! forum_delete_post($post, $fulldelete)) {
				$result = false;
			}
		}
	}

	forum_tp_delete_read_records(-1, -1, $discussion->id);

	if (! delete_records("forum_discussions", "id", "$discussion->id")) {
		$result = false;
	}

	return $result;
}


/**
 *
 */
function forum_delete_post($post, $children=false) {
   if ($childposts = get_records('forum_posts', 'parent', $post->id)) {
	   if ($children) {
		   foreach ($childposts as $childpost) {
			   forum_delete_post($childpost, true);
		   }
	   } else {
		   return false;
	   }
   }
   if (delete_records("forum_posts", "id", $post->id)) {
	   delete_records("forum_ratings", "post", $post->id);  // Just in case

	   forum_tp_delete_read_records(-1, $post->id);

	   if ($post->attachment) {
		   $discussion = get_record("forum_discussions", "id", $post->discussion);
		   $post->course = $discussion->course;
		   $post->forum  = $discussion->forum;
		   forum_delete_old_attachments($post);
	   }

   // Just in case we are deleting the last post
	   forum_discussion_update_last_post($post->discussion);

	   return true;
   }
   return false;
}

/**
 *
 */
function forum_count_replies($post, $children=true) {
	$count = 0;

	if ($children) {
		if ($childposts = get_records('forum_posts', 'parent', $post->id)) {
		   foreach ($childposts as $childpost) {
			   $count ++;				   // For this child
			   $count += forum_count_replies($childpost, true);
		   }
		}
	} else {
		$count += count_records('forum_posts', 'parent', $post->id);
	}

	return $count;
}


/**
 *
 */
function forum_forcesubscribe($forumid, $value=1) {
	return set_field("forum", "forcesubscribe", $value, "id", $forumid);
}

/**
 *
 */
function forum_is_forcesubscribed($forum) {
	if (isset($forum->forcesubscribe)) {	// then we use that
		return ($forum->forcesubscribe == FORUM_FORCESUBSCRIBE);
	} else {   // Check the database
	   return (get_field('forum', 'forcesubscribe', 'id', $forum) == FORUM_FORCESUBSCRIBE);
	}
}

/**
 *
 */
function forum_is_subscribed($userid, $forum) {
	if (is_numeric($forum)) {
		$forum = get_record('forum', 'id', $forum);
	}
	if (forum_is_forcesubscribed($forum)) {
		return true;
	}
	return record_exists("forum_subscriptions", "userid", $userid, "forum", $forum->id);
}

function forum_get_subscribed_forums($course) {
	global $USER, $CFG;
	$sql = "SELECT f.id
			  FROM {$CFG->prefix}forum f
				   LEFT JOIN {$CFG->prefix}forum_subscriptions fs ON (fs.forum = f.id AND fs.userid = $USER->id)
			 WHERE f.forcesubscribe <> ".FORUM_DISALLOWSUBSCRIBE."
				   AND (f.forcesubscribe = ".FORUM_FORCESUBSCRIBE." OR fs.id IS NOT NULL)";
	if ($subscribed = get_records_sql($sql)) {
		foreach ($subscribed as $s) {
			$subscribed[$s->id] = $s->id;
		}
		return $subscribed;
	} else {
		return array();
	}
}

/**
 * Adds user to the subscriber list
 */
function forum_subscribe($userid, $forumid) {

	if (record_exists("forum_subscriptions", "userid", $userid, "forum", $forumid)) {
		return true;
	}

	$sub = new object();
	$sub->userid  = $userid;
	$sub->forum = $forumid;

	return insert_record("forum_subscriptions", $sub);
}

/**
 * Removes user from the subscriber list
 */
function forum_unsubscribe($userid, $forumid) {
	return delete_records("forum_subscriptions", "userid", $userid, "forum", $forumid);
}

/**
 * Given a new post, subscribes or unsubscribes as appropriate.
 * Returns some text which describes what happened.
 */
function forum_post_subscription($post, $forum) {

	global $USER;
	
	$action = '';
	$subscribed = forum_is_subscribed($USER->id, $forum);
	
	if ($forum->forcesubscribe == FORUM_FORCESUBSCRIBE) { // database ignored
		return "";

	} elseif (($forum->forcesubscribe == FORUM_DISALLOWSUBSCRIBE)
		&& !has_capability('moodle/course:manageactivities', get_context_instance(CONTEXT_COURSE, $forum->course), $USER->id)) {
		if ($subscribed) {
			$action = 'unsubscribe'; // sanity check, following MDL-14558
		} else {
			return "";
		}

	} else { // go with the user's choice
		if (isset($post->subscribe)) {
			// no change
			if ((!empty($post->subscribe) && $subscribed)
				|| (empty($post->subscribe) && !$subscribed)) {
				return "";

			} elseif (!empty($post->subscribe) && !$subscribed) {
				$action = 'subscribe';

			} elseif (empty($post->subscribe) && $subscribed) {
				$action = 'unsubscribe';
			}
		}
	}

	$info = new object();
	$info->name  = fullname($USER);
	$info->forum = format_string($forum->name);

	switch ($action) {
		case 'subscribe':
			forum_subscribe($USER->id, $post->forum);
			return "<p>".get_string("nowsubscribed", "forum", $info)."</p>";
		case 'unsubscribe':
			forum_unsubscribe($USER->id, $post->forum);
			return "<p>".get_string("nownotsubscribed", "forum", $info)."</p>";
	}
}

/**
 * Generate and return the subscribe or unsubscribe link for a forum.
 * @param object $forum the forum. Fields used are $forum->id and $forum->forcesubscribe.
 * @param object $context the context object for this forum.
 * @param array $messages text used for the link in its various states
 *	  (subscribed, unsubscribed, forcesubscribed or cantsubscribe).
 *	  Any strings not passed in are taken from the $defaultmessages array
 *	  at the top of the function.
 * @param
 */
function forum_get_subscribe_link($forum, $context, $messages = array(), $cantaccessagroup = false, $fakelink=true, $backtoindex=false, $subscribed_forums=null) {
	global $CFG, $USER;
	$defaultmessages = array(
		'subscribed' => get_string('unsubscribe', 'forum'),
		'unsubscribed' => get_string('subscribe', 'forum'),
		'cantaccessgroup' => get_string('no'),
		'forcesubscribed' => get_string('everyoneissubscribed', 'forum'),
		'cantsubscribe' => get_string('disallowsubscribe','forum')
	);
	$messages = $messages + $defaultmessages;

	if (forum_is_forcesubscribed($forum)) {
		return $messages['forcesubscribed'];
	} else if ($forum->forcesubscribe == FORUM_DISALLOWSUBSCRIBE && !has_capability('mod/forum:managesubscriptions', $context)) {
		return $messages['cantsubscribe'];
	} else if ($cantaccessagroup) {
		return $messages['cantaccessgroup'];
	} else {
		if (is_null($subscribed_forums)) {
			$subscribed = forum_is_subscribed($USER->id, $forum);
		} else {
			$subscribed = !empty($subscribed_forums[$forum->id]);
		}
		if ($subscribed) {
			$linktext = $messages['subscribed'];
			$linktitle = get_string('subscribestop', 'forum');
		} else {
			$linktext = $messages['unsubscribed'];
			$linktitle = get_string('subscribestart', 'forum');
		}

		$options = array();
		if ($backtoindex) {
			$backtoindexlink = '&amp;backtoindex=1';
			$options['backtoindex'] = 1;
		} else {
			$backtoindexlink = '';
		}
		$link = '';

		if ($fakelink) {
			$link .= <<<EOD
<script type="text/javascript">
//<![CDATA[
var subs_link = document.getElementById("subscriptionlink");
if(subs_link){
	subs_link.innerHTML = "<a title=\"$linktitle\" href='$CFG->wwwroot/mod/forum/subscribe.php?id={$forum->id}{$backtoindexlink}'>$linktext<\/a>";
}
//]]>
</script>
<noscript>
EOD;
		}
		$options ['id'] = $forum->id;
		$link .= print_single_button($CFG->wwwroot . '/mod/forum/subscribe.php',
				$options, $linktext, 'post', '_self', true, $linktitle);
		if ($fakelink) {
			$link .= '</noscript>';
		}

		return $link;
	}
}


/**
 * Generate and return the track or no track link for a forum.
 * @param object $forum the forum. Fields used are $forum->id and $forum->forcesubscribe.
 */
function forum_get_tracking_link($forum, $messages=array(), $fakelink=true) {
	global $CFG, $USER;

	static $strnotrackforum, $strtrackforum;

	if (isset($messages['trackforum'])) {
		 $strtrackforum = $messages['trackforum'];
	}
	if (isset($messages['notrackforum'])) {
		 $strnotrackforum = $messages['notrackforum'];
	}
	if (empty($strtrackforum)) {
		$strtrackforum = get_string('trackforum', 'forum');
	}
	if (empty($strnotrackforum)) {
		$strnotrackforum = get_string('notrackforum', 'forum');
	}

	if (forum_tp_is_tracked($forum)) {
		$linktitle = $strnotrackforum;
		$linktext = $strnotrackforum;
	} else {
		$linktitle = $strtrackforum;
		$linktext = $strtrackforum;
	} 

	$link = '';
	if ($fakelink) {
		$link .= '<script type="text/javascript">';
		$link .= '//<![CDATA['."\n";
		$link .= 'document.getElementById("trackinglink").innerHTML = "<a title=\"' . $linktitle . '\" href=\"' . $CFG->wwwroot .
		   '/mod/forum/settracking.php?id=' . $forum->id . '\">' . $linktext . '<\/a>";'."\n";
		$link .= '//]]>'."\n";
		$link .= '</script>';
		// use <noscript> to print button in case javascript is not enabled
		$link .= '<noscript>';
	}
	$link .= print_single_button($CFG->wwwroot . '/mod/forum/settracking.php?id=' . $forum->id,
			'', $linktext, 'post', '_self', true, $linktitle);
	if ($fakelink) {
		$link .= '</noscript>';
	}

	return $link;
}



/**
 * Returns true if user created new discussion already
 * @param int $forumid
 * @param int $userid
 * @return bool
 */
function forum_user_has_posted_discussion($forumid, $userid) {
	global $CFG;

	$sql = "SELECT 'x'
			  FROM {$CFG->prefix}forum_discussions d, {$CFG->prefix}forum_posts p
			 WHERE d.forum = $forumid AND p.discussion = d.id AND p.parent = 0 and p.userid = $userid";

	return record_exists_sql($sql);
}

/**
 *
 */
function forum_discussions_user_has_posted_in($forumid, $userid) {
	global $CFG;

	$haspostedsql = "SELECT d.id AS id,
							d.*
					   FROM {$CFG->prefix}forum_posts p,
							{$CFG->prefix}forum_discussions d
					  WHERE p.discussion = d.id
						AND d.forum = $forumid
						AND p.userid = $userid";

	return get_records_sql($haspostedsql);
}

/**
 *
 */
function forum_user_has_posted($forumid, $did, $userid) {
	global $CFG;

	if (empty($did)) {
		// posted in any forum discussion?
		$sql = "SELECT 'x'
				  FROM {$CFG->prefix}forum_posts p
				  JOIN {$CFG->prefix}forum_discussions d ON d.id = p.discussion
				 WHERE p.userid = $userid AND d.forum = $forumid";
		return record_exists_sql($sql);
	} else {
		// started discussion?
		return record_exists('forum_posts','discussion',$did,'userid',$userid);
	}
}

/**
 *
 */
function forum_user_can_post_discussion($forum, $currentgroup=null, $unused=-1, $cm=NULL, $context=NULL) {
// $forum is an object
	global $USER;

	// shortcut - guest and not-logged-in users can not post
	if (isguestuser() or !isloggedin()) {
		return false;
	}

	if (!$cm) {
		debugging('missing cm', DEBUG_DEVELOPER);
		if (!$cm = get_coursemodule_from_instance('forum', $forum->id, $forum->course)) {
			error('Course Module ID was incorrect');
		}
	}

	if (!$context) {
		$context = get_context_instance(CONTEXT_MODULE, $cm->id);
	}

	if ($currentgroup === null) {
		$currentgroup = groups_get_activity_group($cm);
	}

	$groupmode = groups_get_activity_groupmode($cm);

	if ($forum->type == 'news') {
		$capname = 'mod/forum:addnews';
	} else {
		$capname = 'mod/forum:startdiscussion';
	}

	if (!has_capability($capname, $context)) {
		return false;
	}

	if ($forum->type == 'eachuser') {
		if (forum_user_has_posted_discussion($forum->id, $USER->id)) {
			return false;
		}
	}

	if (!$groupmode or has_capability('moodle/site:accessallgroups', $context)) {
		return true;
	}

	if ($currentgroup) {
		return groups_is_member($currentgroup);
	} else {
		// no group membership and no accessallgroups means no new discussions
		// reverted to 1.7 behaviour in 1.9+,  buggy in 1.8.0-1.9.0
		return false;
	}
}

/**
 * This function checks whether the user can reply to posts in a forum
 * discussion. Use forum_user_can_post_discussion() to check whether the user
 * can start dicussions.
 * @param $forum - forum object
 * @param $user - user object
 */
function forum_user_can_post($forum, $discussion, $user=NULL, $cm=NULL, $course=NULL, $context=NULL) {
	global $USER;
	if (empty($user)) {
		$user = $USER;
	}

	// shortcut - guest and not-logged-in users can not post
	if (isguestuser($user) or empty($user->id)) {
		return false;
	}

	if (!isset($discussion->groupid)) {
		debugging('incorrect discussion parameter', DEBUG_DEVELOPER);
		return false;
	}

	if (!$cm) {
		debugging('missing cm', DEBUG_DEVELOPER);
		if (!$cm = get_coursemodule_from_instance('forum', $forum->id, $forum->course)) {
			error('Course Module ID was incorrect');
		}
	}

	if (!$course) {
		debugging('missing course', DEBUG_DEVELOPER);
		if (!$course = get_record('course', 'id', $forum->course)) {
			error('Incorrect course id');
		}
	}

	if (!$context) {
		$context = get_context_instance(CONTEXT_MODULE, $cm->id);
	}

	// normal users with temporary guest access can not post
	if (has_capability('moodle/legacy:guest', $context, $user->id, false)) {
		return false;
	}

	if ($forum->type == 'news') {
		$capname = 'mod/forum:replynews';
	} else {
		$capname = 'mod/forum:replypost';
	}

	if (!has_capability($capname, $context, $user->id, false)) {
		return false;
	}

	if (!$groupmode = groups_get_activity_groupmode($cm, $course)) {
		return true;
	}

	if (has_capability('moodle/site:accessallgroups', $context)) {
		return true;
	}

	if ($groupmode == VISIBLEGROUPS) {
		if ($discussion->groupid == -1) {
			// allow students to reply to all participants discussions - this was not possible in Moodle <1.8
			return true;
		}
		return groups_is_member($discussion->groupid);

	} else {
		//separate groups
		if ($discussion->groupid == -1) {
			return false;
		}
		return groups_is_member($discussion->groupid);
	}
}


//checks to see if a user can view a particular post
function forum_user_can_view_post($post, $course, $cm, $forum, $discussion, $user=NULL){

	global $CFG, $USER;

	if (!$user){
		$user = $USER;
	}

	$modcontext = get_context_instance(CONTEXT_MODULE, $cm->id);
	if (!has_capability('mod/forum:viewdiscussion', $modcontext)) {
		return false;
	}

// If it's a grouped discussion, make sure the user is a member
	if ($discussion->groupid > 0) {
		$groupmode = groups_get_activity_groupmode($cm);
		if ($groupmode == SEPARATEGROUPS) {
			return groups_is_member($discussion->groupid) || has_capability('moodle/site:accessallgroups', $modcontext);
		}
	}
	return true;
}


/**
 *
 */
function forum_user_can_see_discussion($forum, $discussion, $context, $user=NULL) {
	global $USER;

	if (empty($user) || empty($user->id)) {
		$user = $USER;
	}

	// retrieve objects (yuk)
	if (is_numeric($forum)) {
		debugging('missing full forum', DEBUG_DEVELOPER);
		if (!$forum = get_record('forum','id',$forum)) {
			return false;
		}
	}
	if (is_numeric($discussion)) {
		debugging('missing full discussion', DEBUG_DEVELOPER);
		if (!$discussion = get_record('forum_discussions','id',$discussion)) {
			return false;
		}
	}

	if (!has_capability('mod/forum:viewdiscussion', $context)) {
		return false;
	}

	if ($forum->type == 'qanda' &&
			!forum_user_has_posted($forum->id, $discussion->id, $user->id) &&
			!has_capability('mod/forum:viewqandawithoutposting', $context)) {
		return false;
	}
	return true;
}


/**
 *
 */
function forum_user_can_see_post($forum, $discussion, $post, $user=NULL, $cm=NULL) {
	global $USER;

	// retrieve objects (yuk)
	if (is_numeric($forum)) {
		debugging('missinf full forum', DEBUG_DEVELOPER);
		if (!$forum = get_record('forum','id',$forum)) {
			return false;
		}
	}

	if (is_numeric($discussion)) {
		debugging('missinf full discussion', DEBUG_DEVELOPER);
		if (!$discussion = get_record('forum_discussions','id',$discussion)) {
			return false;
		}
	}
	if (is_numeric($post)) {
		debugging('missinf full post', DEBUG_DEVELOPER);
		if (!$post = get_record('forum_posts','id',$post)) {
			return false;
		}
	}
	if (!isset($post->id) && isset($post->parent)) {
		$post->id = $post->parent;
	}

	if (!$cm) {
		debugging('missing cm', DEBUG_DEVELOPER);
		if (!$cm = get_coursemodule_from_instance('forum', $forum->id, $forum->course)) {
			error('Course Module ID was incorrect');
		}
	}

	if (empty($user) || empty($user->id)) {
		$user = $USER;
	}

	if (isset($cm->cache->caps['mod/forum:viewdiscussion'])) {
		if (!$cm->cache->caps['mod/forum:viewdiscussion']) {
			return false;
		}
	} else {
		$modcontext = get_context_instance(CONTEXT_MODULE, $cm->id);
		if (!has_capability('mod/forum:viewdiscussion', $modcontext, $user->id)) {
			return false;
		}
	}

	if (isset($cm->uservisible)) {
		if (!$cm->uservisible) {
			return false;
		}
	} else {
		if (!coursemodule_visible_for_user($cm, $user->id)) {
			return false;
		}
	}

	if ($forum->type == 'qanda') {
		$firstpost = forum_get_firstpost_from_discussion($discussion->id);
		$modcontext = get_context_instance(CONTEXT_MODULE, $cm->id);

		return (forum_user_has_posted($forum->id,$discussion->id,$user->id) ||
				$firstpost->id == $post->id ||
				has_capability('mod/forum:viewqandawithoutposting', $modcontext, $user->id, false));
	}
	return true;
}


/**
 * Prints the discussion view screen for a forum.
 *
 * @param object $course The current course object.
 * @param object $forum Forum to be printed.
 * @param int $maxdiscussions .
 * @param string $displayformat The display format to use (optional).
 * @param string $sort Sort arguments for database query (optional).
 * @param int $groupmode Group mode of the forum (optional).
 * @param void $unused (originally current group)
 * @param int $page Page mode, page to display (optional).
 * @param int perpage The maximum number of discussions per page(optional)
 *
 */
function forum_print_latest_discussions($course, $forum, $maxdiscussions=-1, $displayformat='plain', $sort='',
										$currentgroup=-1, $groupmode=-1, $page=-1, $perpage=100, $cm=NULL) {
	global $CFG, $USER;

	if (!$cm) {
		if (!$cm = get_coursemodule_from_instance('forum', $forum->id, $forum->course)) {
			error('Course Module ID was incorrect');
		}
	}
	$context = get_context_instance(CONTEXT_MODULE, $cm->id);

	if (empty($sort)) {
		$sort = "d.timemodified DESC";
	}

	$olddiscussionlink = false;

 // Sort out some defaults
	if ($perpage <= 0) {
		$perpage = 0;
		$page	= -1;
	}

	if ($maxdiscussions == 0) {
		// all discussions - backwards compatibility
		$page	= -1;
		$perpage = 0;
		if ($displayformat == 'plain') {
			$displayformat = 'header';  // Abbreviate display by default
		}

	} else if ($maxdiscussions > 0) {
		$page	= -1;
		$perpage = $maxdiscussions;
	}

	$fullpost = false;
	if ($displayformat == 'plain') {
		$fullpost = true;
	}


// Decide if current user is allowed to see ALL the current discussions or not

// First check the group stuff
	if ($currentgroup == -1 or $groupmode == -1) {
		$groupmode	= groups_get_activity_groupmode($cm, $course);
		$currentgroup = groups_get_activity_group($cm);
	}

// If the user can post discussions, then this is a good place to put the
// button for it. We do not show the button if we are showing site news
// and the current user is a guest.

	if (forum_user_can_post_discussion($forum, $currentgroup, $groupmode, $cm, $context) ||
		($forum->type != 'news'
		 and (isguestuser() or !isloggedin() or has_capability('moodle/legacy:guest', $context, NULL, false))) ) {

		echo '<div class="singlebutton forumaddnew">';
		echo "<form id=\"newdiscussionform\" method=\"get\" action=\"$CFG->wwwroot/mod/forum/post.php\">";
		echo '<div>';
		echo "<input type=\"hidden\" name=\"forum\" value=\"$forum->id\" />";
		echo '<input type="submit" value="';
		echo ($forum->type == 'news') ? get_string('addanewtopic', 'forum')
			: (($forum->type == 'qanda')
			   ? get_string('addanewquestion','forum')
			   : get_string('addanewdiscussion', 'forum'));
		echo '" />';
		echo '</div>';
		echo '</form>';
		echo "</div>\n";

	} else if (isguestuser() or !isloggedin() or $forum->type == 'news') {
		// no button and no info

	} else if ($groupmode and has_capability('mod/forum:startdiscussion', $context)) {
		// inform users why they can not post new discussion
		if ($currentgroup) {
			notify(get_string('cannotadddiscussion', 'forum'));
		} else {
			notify(get_string('cannotadddiscussionall', 'forum'));
		}
	}

// Get all the recent discussions we're allowed to see

	$getuserlastmodified = ($displayformat == 'header');

	if (! $discussions = forum_get_discussions($cm, $sort, $fullpost, null, $maxdiscussions, $getuserlastmodified, $page, $perpage) ) {
		echo '<div class="forumnodiscuss">';
		if ($forum->type == 'news') {
			echo '('.get_string('nonews', 'forum').')';
		} else if ($forum->type == 'qanda') {
			echo '('.get_string('noquestions','forum').')';
		} else {
			echo '('.get_string('nodiscussions', 'forum').')';
		}
		echo "</div>\n";
		return;
	}

// If we want paging
	if ($page != -1) {
		///Get the number of discussions found
		$numdiscussions = forum_get_discussions_count($cm);

		///Show the paging bar
		print_paging_bar($numdiscussions, $page, $perpage, "view.php?f=$forum->id&amp;");
		if ($numdiscussions > 1000) {
			// saves some memory on sites with very large forums
			$replies = forum_count_discussion_replies($forum->id, $sort, $maxdiscussions, $page, $perpage);
		} else {
			$replies = forum_count_discussion_replies($forum->id);
		}

	} else {
		$replies = forum_count_discussion_replies($forum->id);

		if ($maxdiscussions > 0 and $maxdiscussions <= count($discussions)) {
			$olddiscussionlink = true;
		}
	}

	$canviewparticipants = has_capability('moodle/course:viewparticipants',$context);

	$strdatestring = get_string('strftimerecentfull');

	// Check if the forum is tracked.
	if ($cantrack = forum_tp_can_track_forums($forum)) {
		$forumtracked = forum_tp_is_tracked($forum);
	} else {
		$forumtracked = false;
	}

	if ($forumtracked) {
		$unreads = forum_get_discussions_unread($cm);
	} else {
		$unreads = array();
	}

	if ($displayformat == 'header') {
		echo '<table cellspacing="0" class="forumheaderlist">';
		echo '<thead>';
		echo '<tr>';
		echo '<th class="header topic" scope="col">'.get_string('discussion', 'forum').'</th>';
		echo '<th class="header author" colspan="2" scope="col">'.get_string('startedby', 'forum').'</th>';
		if ($groupmode > 0) {
			echo '<th class="header group" scope="col">'.get_string('group').'</th>';
		}
		if (has_capability('mod/forum:viewdiscussion', $context)) {
			echo '<th class="header replies" scope="col">'.get_string('replies', 'forum').'</th>';
			// If the forum can be tracked, display the unread column.
			if ($cantrack) {
				echo '<th class="header replies" scope="col">'.get_string('unread', 'forum');
				if ($forumtracked) {
					echo '&nbsp;<a title="'.get_string('markallread', 'forum').
						 '" href="'.$CFG->wwwroot.'/mod/forum/markposts.php?f='.
						 $forum->id.'&amp;mark=read&amp;returnpage=view.php">'.
						 '<img src="'.$CFG->pixpath.'/t/clear.gif" class="iconsmall" alt="'.get_string('markallread', 'forum').'" /></a>';
				}
				echo '</th>';
			}
		}
		echo '<th class="header lastpost" scope="col">'.get_string('lastpost', 'forum').'</th>';
		echo '</tr>';
		echo '</thead>';
		echo '<tbody>';
	}

	foreach ($discussions as $discussion) {
		if (!empty($replies[$discussion->discussion])) {
			$discussion->replies = $replies[$discussion->discussion]->replies;
			$discussion->lastpostid = $replies[$discussion->discussion]->lastpostid;
		} else {
			$discussion->replies = 0;
		}

		// SPECIAL CASE: The front page can display a news item post to non-logged in users.
		// All posts are read in this case.
		if (!$forumtracked) {
			$discussion->unread = '-';
		} else if (empty($USER)) {
			$discussion->unread = 0;
		} else {
			if (empty($unreads[$discussion->discussion])) {
				$discussion->unread = 0;
			} else {
				$discussion->unread = $unreads[$discussion->discussion];
			}
		}

		if (!empty($USER->id)) {
			$ownpost = ($discussion->userid == $USER->id);
		} else {
			$ownpost=false;
		}
		// Use discussion name instead of subject of first post
		$discussion->subject = $discussion->name;

		switch ($displayformat) {
			case 'header':
				if ($groupmode > 0) {
					if (isset($groups[$discussion->groupid])) {
						$group = $groups[$discussion->groupid];
					} else {
						$group = $groups[$discussion->groupid] = groups_get_group($discussion->groupid);
					}
				} else {
					$group = -1;
				}
				forum_print_discussion_header($discussion, $forum, $group, $strdatestring, $cantrack, $forumtracked,
					$canviewparticipants, $context);
			break;
			default:
				$link = false;

				if ($discussion->replies) {
					$link = true;
				} else {
					$modcontext = get_context_instance(CONTEXT_MODULE, $cm->id);
					$link = forum_user_can_post($forum, $discussion, $USER, $cm, $course, $modcontext);
				}

				$discussion->forum = $forum->id;

				forum_print_post($discussion, $discussion, $forum, $cm, $course, $ownpost, 0, $link, false);
			break;
		}
	}

	if ($displayformat == "header") {
		echo '</tbody>';
		echo '</table>';
	}

	if ($olddiscussionlink) {
		if ($forum->type == 'news') {
			$strolder = get_string('oldertopics', 'forum');
		} else {
			$strolder = get_string('olderdiscussions', 'forum');
		}
		echo '<div class="forumolddiscuss">';
		echo '<a href="'.$CFG->wwwroot.'/mod/forum/view.php?f='.$forum->id.'&amp;showall=1">';
		echo $strolder.'</a> ...</div>';
	}

	if ($page != -1) { ///Show the paging bar
		print_paging_bar($numdiscussions, $page, $perpage, "view.php?f=$forum->id&amp;");
	}
}


/**
 *
 */
function forum_print_discussion($course, $cm, $forum, $discussion, $post, $mode, $canreply=NULL, $canrate=false) {

	global $USER, $CFG;

	if (!empty($USER->id)) {
		$ownpost = ($USER->id == $post->userid);
	} else {
		$ownpost = false;
	}
	if ($canreply === NULL) {
		$modcontext = get_context_instance(CONTEXT_MODULE, $cm->id);
		$reply = forum_user_can_post($forum, $discussion, $USER, $cm, $course, $modcontext);
	} else {
		$reply = $canreply;
	}

	// $cm holds general cache for forum functions
	$cm->cache = new object();
	$cm->cache->groups	  = groups_get_all_groups($course->id, 0, $cm->groupingid);
	$cm->cache->usersgroups = array();

	$posters = array();

	// preload all posts - TODO: improve...
	if ($mode == FORUM_MODE_FLATNEWEST) {
		$sort = "p.created DESC";
	} else {
		$sort = "p.created ASC";
	}

	$forumtracked = forum_tp_is_tracked($forum);
	$posts = forum_get_all_discussion_posts($discussion->id, $sort, $forumtracked);
	$post = $posts[$post->id];

	foreach ($posts as $pid=>$p) {
		$posters[$p->userid] = $p->userid;
	}

	// preload all groups of ppl that posted in this discussion
	if ($postersgroups = groups_get_all_groups($course->id, $posters, $cm->groupingid, 'gm.id, gm.groupid, gm.userid')) {
		foreach($postersgroups as $pg) {
			if (!isset($cm->cache->usersgroups[$pg->userid])) {
				$cm->cache->usersgroups[$pg->userid] = array();
			}
			$cm->cache->usersgroups[$pg->userid][$pg->groupid] = $pg->groupid;
		}
		unset($postersgroups);
	}

	$ratings = NULL;
	$ratingsmenuused = false;
	$ratingsformused = false;
	if ($forum->assessed and isloggedin()) {
		if ($scale = make_grades_menu($forum->scale)) {
			$ratings =new object();
			$ratings->scale = $scale;
			$ratings->assesstimestart = $forum->assesstimestart;
			$ratings->assesstimefinish = $forum->assesstimefinish;
			$ratings->allow = $canrate;

			if ($ratings->allow) {
				echo '<form id="form" method="post" action="rate.php">';
				echo '<div class="ratingform">';
				echo '<input type="hidden" name="forumid" value="'.$forum->id.'" />';
				$ratingsformused = true;
			}

			// preload all ratings - one query only and minimal memory
			$cm->cache->ratings = array();
			$cm->cache->myratings = array();
			if ($postratings = forum_get_all_discussion_ratings($discussion)) {
				foreach ($postratings as $pr) {
					if (!isset($cm->cache->ratings[$pr->postid])) {
						$cm->cache->ratings[$pr->postid] = array();
					}
					$cm->cache->ratings[$pr->postid][$pr->id] = $pr->rating;
					if ($pr->userid == $USER->id) {
						$cm->cache->myratings[$pr->postid] = $pr->rating;
					}
				}
				unset($postratings);
			}
		}

	}

	$post->forum = $forum->id;   // Add the forum id to the post object, later used by forum_print_post
	$post->forumtype = $forum->type;

	$post->subject = format_string($post->subject);

	$postread = !empty($post->postread);

	if (forum_print_post($post, $discussion, $forum, $cm, $course, $ownpost, $reply, false, $ratings,
						 '', '', $postread, true, $forumtracked)) {
		$ratingsmenuused = true;
	}

	switch ($mode) {
		case FORUM_MODE_FLATOLDEST :
		case FORUM_MODE_FLATNEWEST :
		default:
			if (forum_print_posts_flat($course, $cm, $forum, $discussion, $post, $mode, $ratings, $reply, $forumtracked, $posts)) {
				$ratingsmenuused = true;
			}
			break;

		case FORUM_MODE_THREADED :
			if (forum_print_posts_threaded($course, $cm, $forum, $discussion, $post, 0, $ratings, $reply, $forumtracked, $posts)) {
				$ratingsmenuused = true;
			}
			break;

		case FORUM_MODE_NESTED :
			if (forum_print_posts_nested($course, $cm, $forum, $discussion, $post, $ratings, $reply, $forumtracked, $posts)) {
				$ratingsmenuused = true;
			}
			break;
	}

	if ($ratingsformused) {
		if ($ratingsmenuused) {
			echo '<div class="ratingsubmit">';
			echo '<input type="submit" id="forumpostratingsubmit" value="'.get_string('sendinratings', 'forum').'" />';
			if (ajaxenabled() && !empty($CFG->forum_ajaxrating)) { /// AJAX enabled, standard submission form
				$rate_ajax_config_settings = array("pixpath"=>$CFG->pixpath, "wwwroot"=>$CFG->wwwroot, "sesskey"=>sesskey());
				echo "<script type=\"text/javascript\">//<![CDATA[\n".
					 "var rate_ajax_config = " . json_encode($rate_ajax_config_settings) . ";\n".
					 "init_rate_ajax();\n".
					 "//]]></script>\n";
			}
			if ($forum->scale < 0) {
				if ($scale = get_record("scale", "id", abs($forum->scale))) {
					print_scale_menu_helpbutton($course->id, $scale );
				}
			}
			echo '</div>';
		}

		echo '</div>';
		echo '</form>';
	}
}


/**
 *
 */
function forum_print_posts_flat($course, &$cm, $forum, $discussion, $post, $mode, $ratings, $reply, $forumtracked, $posts) {
	global $USER, $CFG;

	$link  = false;
	$ratingsmenuused = false;

	if ($mode == FORUM_MODE_FLATNEWEST) {
		$sort = "ORDER BY created DESC";
	} else {
		$sort = "ORDER BY created ASC";
	}

	foreach ($posts as $post) {
		if (!$post->parent) {
			continue;
		}
		$post->subject = format_string($post->subject);
		$ownpost = ($USER->id == $post->userid);

		$postread = !empty($post->postread);

		if (forum_print_post($post, $discussion, $forum, $cm, $course, $ownpost, $reply, $link, $ratings,
							 '', '', $postread, true, $forumtracked)) {
			$ratingsmenuused = true;
		}
	}

	return $ratingsmenuused;
}


/**
 * TODO document
 */
function forum_print_posts_threaded($course, &$cm, $forum, $discussion, $parent, $depth, $ratings, $reply, $forumtracked, $posts) {
	global $USER, $CFG;

	$link  = false;
	$ratingsmenuused = false;

	if (!empty($posts[$parent->id]->children)) {
		$posts = $posts[$parent->id]->children;

		$modcontext	   = get_context_instance(CONTEXT_MODULE, $cm->id);
		$canviewfullnames = has_capability('moodle/site:viewfullnames', $modcontext);

		foreach ($posts as $post) {

			echo '<div class="indent">';
			if ($depth > 0) {
				$ownpost = ($USER->id == $post->userid);
				$post->subject = format_string($post->subject);

				$postread = !empty($post->postread);

				if (forum_print_post($post, $discussion, $forum, $cm, $course, $ownpost, $reply, $link, $ratings,
									 '', '', $postread, true, $forumtracked)) {
					$ratingsmenuused = true;
				}
			} else {
				if (!forum_user_can_see_post($forum, $discussion, $post, NULL, $cm)) {
					continue;
				}
				$by = new object();
				$by->name = fullname($post, $canviewfullnames);
				$by->date = userdate($post->modified);

				if ($forumtracked) {
					if (!empty($post->postread)) {
						$style = '<span class="forumthread read">';
					} else {
						$style = '<span class="forumthread unread">';
					}
				} else {
					$style = '<span class="forumthread">';
				}
				echo $style."<a name=\"$post->id\"></a>".
					 "<a href=\"discuss.php?d=$post->discussion&amp;parent=$post->id\">".format_string($post->subject,true)."</a> ";
				print_string("bynameondate", "forum", $by);
				echo "</span>";
			}

			if (forum_print_posts_threaded($course, $cm, $forum, $discussion, $post, $depth-1, $ratings, $reply, $forumtracked, $posts)) {
				$ratingsmenuused = true;
			}
			echo "</div>\n";
		}
	}
	return $ratingsmenuused;
}

/**
 *
 */
function forum_print_posts_nested($course, &$cm, $forum, $discussion, $parent, $ratings, $reply, $forumtracked, $posts) {
	global $USER, $CFG;

	$link  = false;
	$ratingsmenuused = false;

	if (!empty($posts[$parent->id]->children)) {
		$posts = $posts[$parent->id]->children;

		foreach ($posts as $post) {

			echo '<div class="indent">';
			if (empty($USER->id)) {
				$ownpost = false;
			} else {
				$ownpost = ($USER->id == $post->userid);
			}

			$post->subject = format_string($post->subject);
			$postread = !empty($post->postread);

			if (forum_print_post($post, $discussion, $forum, $cm, $course, $ownpost, $reply, $link, $ratings,
								 '', '', $postread, true, $forumtracked)) {
				$ratingsmenuused = true;
			}
			if (forum_print_posts_nested($course, $cm, $forum, $discussion, $post, $ratings, $reply, $forumtracked, $posts)) {
				$ratingsmenuused = true;
			}
			echo "</div>\n";
		}
	}
	return $ratingsmenuused;
}

/**
 * Returns all forum posts since a given time in specified forum.
 */
function forum_get_recent_mod_activity(&$activities, &$index, $timestart, $courseid, $cmid, $userid=0, $groupid=0)  {
	global $CFG, $COURSE, $USER;

	if ($COURSE->id == $courseid) {
		$course = $COURSE;
	} else {
		$course = get_record('course', 'id', $courseid);
	}

	$modinfo =& get_fast_modinfo($course);

	$cm = $modinfo->cms[$cmid];

	if ($userid) {
		$userselect = "AND u.id = $userid";
	} else {
		$userselect = "";
	}

	if ($groupid) {
		$groupselect = "AND gm.groupid = $groupid";
		$groupjoin   = "JOIN {$CFG->prefix}groups_members gm ON  gm.userid=u.id";
	} else {
		$groupselect = "";
		$groupjoin   = "";
	}

	if (!$posts = get_records_sql("SELECT p.*, f.type AS forumtype, d.forum, d.groupid,
										  d.timestart, d.timeend, d.userid AS duserid,
										  u.firstname, u.lastname, u.email, u.picture, u.imagealt
									 FROM {$CFG->prefix}forum_posts p
										  JOIN {$CFG->prefix}forum_discussions d ON d.id = p.discussion
										  JOIN {$CFG->prefix}forum f			 ON f.id = d.forum
										  JOIN {$CFG->prefix}user u			  ON u.id = p.userid
										  $groupjoin
									WHERE p.created > $timestart AND f.id = $cm->instance
										  $userselect $groupselect
								 ORDER BY p.id ASC")) { // order by initial posting date
		 return;
	}

	$groupmode	   = groups_get_activity_groupmode($cm, $course);
	$cm_context	  = get_context_instance(CONTEXT_MODULE, $cm->id);
	$viewhiddentimed = has_capability('mod/forum:viewhiddentimedposts', $cm_context);
	$accessallgroups = has_capability('moodle/site:accessallgroups', $cm_context);

	if (is_null($modinfo->groups)) {
		$modinfo->groups = groups_get_user_groups($course->id); // load all my groups and cache it in modinfo
	}

	$printposts = array();
	foreach ($posts as $post) {

		if (!empty($CFG->forum_enabletimedposts) and $USER->id != $post->duserid
		  and (($post->timestart > 0 and $post->timestart > time()) or ($post->timeend > 0 and $post->timeend < time()))) {
			if (!$viewhiddentimed) {
				continue;
			}
		}

		if ($groupmode) {
			if ($post->groupid == -1 or $groupmode == VISIBLEGROUPS or $accessallgroups) {
				// oki (Open discussions have groupid -1)
			} else {
				// separate mode
				if (isguestuser()) {
					// shortcut
					continue;
				}

				if (!array_key_exists($post->groupid, $modinfo->groups[0])) {
					continue;
				}
			}
		}

		$printposts[] = $post;
	}

	if (!$printposts) {
		return;
	}

	$aname = format_string($cm->name,true);

	foreach ($printposts as $post) {
		$tmpactivity = new object();

		$tmpactivity->type		 = 'forum';
		$tmpactivity->cmid		 = $cm->id;
		$tmpactivity->name		 = $aname;
		$tmpactivity->sectionnum   = $cm->sectionnum;
		$tmpactivity->timestamp	= $post->modified;

		$tmpactivity->content = new object();
		$tmpactivity->content->id		 = $post->id;
		$tmpactivity->content->discussion = $post->discussion;
		$tmpactivity->content->subject	= format_string($post->subject);
		$tmpactivity->content->parent	 = $post->parent;

		$tmpactivity->user = new object();
		$tmpactivity->user->id		= $post->userid;
		$tmpactivity->user->firstname = $post->firstname;
		$tmpactivity->user->lastname  = $post->lastname;
		$tmpactivity->user->picture   = $post->picture;
		$tmpactivity->user->imagealt  = $post->imagealt;
		$tmpactivity->user->email	 = $post->email;

		$activities[$index++] = $tmpactivity;
	}

	return;
}

/**
 *
 */
function forum_print_recent_mod_activity($activity, $courseid, $detail, $modnames, $viewfullnames) {
	global $CFG;

	if ($activity->content->parent) {
		$class = 'reply';
	} else {
		$class = 'discussion';
	}

	echo '<table border="0" cellpadding="3" cellspacing="0" class="forum-recent">';

	echo "<tr><td class=\"userpicture\" valign=\"top\">";
	print_user_picture($activity->user, $courseid);
	echo "</td><td class=\"$class\">";

	echo '<div class="title">';
	if ($detail) {
		$aname = s($activity->name);
		echo "<img src=\"$CFG->modpixpath/$activity->type/icon.gif\" ".
			 "class=\"icon\" alt=\"{$aname}\" />";
	}
	echo "<a href=\"$CFG->wwwroot/mod/forum/discuss.php?d={$activity->content->discussion}"
		 ."#p{$activity->content->id}\">{$activity->content->subject}</a>";
	echo '</div>';

	echo '<div class="user">';
	$fullname = fullname($activity->user, $viewfullnames);
	echo "<a href=\"$CFG->wwwroot/user/view.php?id={$activity->user->id}&amp;course=$courseid\">"
		 ."{$fullname}</a> - ".userdate($activity->timestamp);
	echo '</div>';
	  echo "</td></tr></table>";

	return;
}

/**
 * recursively sets the discussion field to $discussionid on $postid and all its children
 * used when pruning a post
 */
function forum_change_discussionid($postid, $discussionid) {
	set_field('forum_posts', 'discussion', $discussionid, 'id', $postid);
	if ($posts = get_records('forum_posts', 'parent', $postid)) {
		foreach ($posts as $post) {
			forum_change_discussionid($post->id, $discussionid);
		}
	}
	return true;
}

/**
 * Prints the editing button on subscribers page
 */
function forum_update_subscriptions_button($courseid, $forumid) {
	global $CFG, $USER;

	if (!empty($USER->subscriptionsediting)) {
		$string = get_string('turneditingoff');
		$edit = "off";
	} else {
		$string = get_string('turneditingon');
		$edit = "on";
	}

	return "<form $CFG->frametarget method=\"get\" action=\"$CFG->wwwroot/mod/forum/subscribers.php\">".
		   "<input type=\"hidden\" name=\"id\" value=\"$forumid\" />".
		   "<input type=\"hidden\" name=\"edit\" value=\"$edit\" />".
		   "<input type=\"submit\" value=\"$string\" /></form>";
}

/*
 * This function gets run whenever a role is assigned to a user in a context
 *
 * @param integer $userid
 * @param object $context
 * @return bool
 */
function forum_role_assign($userid, $context, $roleid) {
	// check to see if this role comes with mod/forum:initialsubscriptions
	$cap = role_context_capabilities($roleid, $context, 'mod/forum:initialsubscriptions');
	$cap1 = role_context_capabilities($roleid, $context, 'moodle/course:view');
	// we are checking the role because has_capability() will pull this capability out
	// from other roles this user might have and resolve them, which is no good
	// the role needs course view to
	if (isset($cap['mod/forum:initialsubscriptions']) && $cap['mod/forum:initialsubscriptions'] == CAP_ALLOW &&
		isset($cap1['moodle/course:view']) && $cap1['moodle/course:view'] == CAP_ALLOW) {
		return forum_add_user_default_subscriptions($userid, $context);
	} else {
		// MDL-8981, do not subscribe to forum
		return true;
	}
}


/**
 * This function gets run whenever a role is assigned to a user in a context
 *
 * @param integer $userid
 * @param object $context
 * @return bool
 */
function forum_role_unassign($userid, $context) {
	if (empty($context->contextlevel)) {
		return false;
	}

	forum_remove_user_subscriptions($userid, $context);
	forum_remove_user_tracking($userid, $context);

	return true;
}


/**
 * Add subscriptions for new users
 */
function forum_add_user_default_subscriptions($userid, $context) {

	if (empty($context->contextlevel)) {
		return false;
	}

	switch ($context->contextlevel) {

		case CONTEXT_SYSTEM:   // For the whole site
			 if ($courses = get_records('course')) {
				 foreach ($courses as $course) {
					 $subcontext = get_context_instance(CONTEXT_COURSE, $course->id);
					 forum_add_user_default_subscriptions($userid, $subcontext);
				 }
			 }
			 break;

		case CONTEXT_COURSECAT:   // For a whole category
			 if ($courses = get_records('course', 'category', $context->instanceid)) {
				 foreach ($courses as $course) {
					 $subcontext = get_context_instance(CONTEXT_COURSE, $course->id);
					 forum_add_user_default_subscriptions($userid, $subcontext);
				 }
			 }
			 if ($categories = get_records('course_categories', 'parent', $context->instanceid)) {
				 foreach ($categories as $category) {
					 $subcontext = get_context_instance(CONTEXT_COURSECAT, $category->id);
					 forum_add_user_default_subscriptions($userid, $subcontext);
				 }
			 }
			 break;


		case CONTEXT_COURSE:   // For a whole course
			 if ($course = get_record('course', 'id', $context->instanceid)) {
				 if ($forums = get_all_instances_in_course('forum', $course, $userid, false)) {
					 foreach ($forums as $forum) {
						 if ($forum->forcesubscribe != FORUM_INITIALSUBSCRIBE) {
							 continue;
						 }
						 if ($modcontext = get_context_instance(CONTEXT_MODULE, $forum->coursemodule)) {
							 if (has_capability('mod/forum:viewdiscussion', $modcontext, $userid)) {
								 forum_subscribe($userid, $forum->id);
							 }
						 }
					 }
				 }
			 }
			 break;

		case CONTEXT_MODULE:   // Just one forum
			 if ($cm = get_coursemodule_from_id('forum', $context->instanceid)) {
				 if ($forum = get_record('forum', 'id', $cm->instance)) {
					 if ($forum->forcesubscribe != FORUM_INITIALSUBSCRIBE) {
						 continue;
					 }
					 if (has_capability('mod/forum:viewdiscussion', $context, $userid)) {
						 forum_subscribe($userid, $forum->id);
					 }
				 }
			 }
			 break;
	}

	return true;
}


/**
 * Remove subscriptions for a user in a context
 */
function forum_remove_user_subscriptions($userid, $context) {

	global $CFG;

	if (empty($context->contextlevel)) {
		return false;
	}

	switch ($context->contextlevel) {

		case CONTEXT_SYSTEM:   // For the whole site
			//if ($courses = get_my_courses($userid)) {
			// find all courses in which this user has a forum subscription
			if ($courses = get_records_sql("SELECT c.id
											  FROM {$CFG->prefix}course c,
												   {$CFG->prefix}forum_subscriptions fs,
												   {$CFG->prefix}forum f
												   WHERE c.id = f.course AND f.id = fs.forum AND fs.userid = $userid
												   GROUP BY c.id")) {

				foreach ($courses as $course) {
					$subcontext = get_context_instance(CONTEXT_COURSE, $course->id);
					forum_remove_user_subscriptions($userid, $subcontext);
				}
			}
			break;

		case CONTEXT_COURSECAT:   // For a whole category
			 if ($courses = get_records('course', 'category', $context->instanceid, '', 'id')) {
				 foreach ($courses as $course) {
					 $subcontext = get_context_instance(CONTEXT_COURSE, $course->id);
					 forum_remove_user_subscriptions($userid, $subcontext);
				 }
			 }
			 if ($categories = get_records('course_categories', 'parent', $context->instanceid, '', 'id')) {
				 foreach ($categories as $category) {
					 $subcontext = get_context_instance(CONTEXT_COURSECAT, $category->id);
					 forum_remove_user_subscriptions($userid, $subcontext);
				 }
			 }
			 break;

		case CONTEXT_COURSE:   // For a whole course
			 if ($course = get_record('course', 'id', $context->instanceid, '', '', '', '', 'id')) {
				// find all forums in which this user has a subscription, and its coursemodule id
				if ($forums = get_records_sql("SELECT f.id, cm.id as coursemodule
												 FROM {$CFG->prefix}forum f,
													  {$CFG->prefix}modules m,
													  {$CFG->prefix}course_modules cm,
													  {$CFG->prefix}forum_subscriptions fs
												WHERE fs.userid = $userid AND f.course = $context->instanceid
													  AND fs.forum = f.id AND cm.instance = f.id
													  AND cm.module = m.id AND m.name = 'forum'")) {

					 foreach ($forums as $forum) {
						 if ($modcontext = get_context_instance(CONTEXT_MODULE, $forum->coursemodule)) {
							 if (!has_capability('mod/forum:viewdiscussion', $modcontext, $userid)) {
								 forum_unsubscribe($userid, $forum->id);
							 }
						 }
					 }
				 }
			 }
			 break;

		case CONTEXT_MODULE:   // Just one forum
			 if ($cm = get_coursemodule_from_id('forum', $context->instanceid)) {
				 if ($forum = get_record('forum', 'id', $cm->instance)) {
					 if (!has_capability('mod/forum:viewdiscussion', $context, $userid)) {
						 forum_unsubscribe($userid, $forum->id);
					 }
				 }
			 }
			 break;
	}

	return true;
}

// Functions to do with read tracking.

/**
 * Remove post tracking for a user in a context
 */
function forum_remove_user_tracking($userid, $context) {

	global $CFG;

	if (empty($context->contextlevel)) {
		return false;
	}

	switch ($context->contextlevel) {

		case CONTEXT_SYSTEM:   // For the whole site
			// find all courses in which this user has tracking info
			$allcourses = array();
			if ($courses = get_records_sql("SELECT c.id
											  FROM {$CFG->prefix}course c,
												   {$CFG->prefix}forum_read fr,
												   {$CFG->prefix}forum f
												   WHERE c.id = f.course AND f.id = fr.forumid AND fr.userid = $userid
												   GROUP BY c.id")) {

				$allcourses = $allcourses + $courses;
			}
			if ($courses = get_records_sql("SELECT c.id
											  FROM {$CFG->prefix}course c,
												   {$CFG->prefix}forum_track_prefs ft,
												   {$CFG->prefix}forum f
											 WHERE c.id = f.course AND f.id = ft.forumid AND ft.userid = $userid")) {

				$allcourses = $allcourses + $courses;
			}
			foreach ($allcourses as $course) {
				$subcontext = get_context_instance(CONTEXT_COURSE, $course->id);
				forum_remove_user_tracking($userid, $subcontext);
			}
			break;

		case CONTEXT_COURSECAT:   // For a whole category
			 if ($courses = get_records('course', 'category', $context->instanceid, '', 'id')) {
				 foreach ($courses as $course) {
					 $subcontext = get_context_instance(CONTEXT_COURSE, $course->id);
					 forum_remove_user_tracking($userid, $subcontext);
				 }
			 }
			 if ($categories = get_records('course_categories', 'parent', $context->instanceid, '', 'id')) {
				 foreach ($categories as $category) {
					 $subcontext = get_context_instance(CONTEXT_COURSECAT, $category->id);
					 forum_remove_user_tracking($userid, $subcontext);
				 }
			 }
			 break;

		case CONTEXT_COURSE:   // For a whole course
			 if ($course = get_record('course', 'id', $context->instanceid, '', '', '', '', 'id')) {
				// find all forums in which this user has reading tracked
				if ($forums = get_records_sql("SELECT f.id, cm.id as coursemodule
												 FROM {$CFG->prefix}forum f,
													  {$CFG->prefix}modules m,
													  {$CFG->prefix}course_modules cm,
													  {$CFG->prefix}forum_read fr
												WHERE fr.userid = $userid AND f.course = $context->instanceid
													  AND fr.forumid = f.id AND cm.instance = f.id
													  AND cm.module = m.id AND m.name = 'forum'")) {

					 foreach ($forums as $forum) {
						 if ($modcontext = get_context_instance(CONTEXT_MODULE, $forum->coursemodule)) {
							 if (!has_capability('mod/forum:viewdiscussion', $modcontext, $userid)) {
								forum_tp_delete_read_records($userid, -1, -1, $forum->id);
							 }
						 }
					 }
				 }

				// find all forums in which this user has a disabled tracking
				if ($forums = get_records_sql("SELECT f.id, cm.id as coursemodule
												 FROM {$CFG->prefix}forum f,
													  {$CFG->prefix}modules m,
													  {$CFG->prefix}course_modules cm,
													  {$CFG->prefix}forum_track_prefs ft
												WHERE ft.userid = $userid AND f.course = $context->instanceid
													  AND ft.forumid = f.id AND cm.instance = f.id
													  AND cm.module = m.id AND m.name = 'forum'")) {

					 foreach ($forums as $forum) {
						 if ($modcontext = get_context_instance(CONTEXT_MODULE, $forum->coursemodule)) {
							 if (!has_capability('mod/forum:viewdiscussion', $modcontext, $userid)) {
								delete_records('forum_track_prefs', 'userid', $userid, 'forumid', $forum->id);
							 }
						 }
					 }
				 }
			 }
			 break;

		case CONTEXT_MODULE:   // Just one forum
			 if ($cm = get_coursemodule_from_id('forum', $context->instanceid)) {
				 if ($forum = get_record('forum', 'id', $cm->instance)) {
					 if (!has_capability('mod/forum:viewdiscussion', $context, $userid)) {
						delete_records('forum_track_prefs', 'userid', $userid, 'forumid', $forum->id);
						forum_tp_delete_read_records($userid, -1, -1, $forum->id);
					 }
				 }
			 }
			 break;
	}

	return true;
}

/**
 * Mark posts as read.
 * @param object $user object
 * @param array $postids array of post ids
 * @return boolean success
 */
function forum_tp_mark_posts_read($user, $postids) {
	global $CFG;

	if (!forum_tp_can_track_forums(false, $user)) {
		return true;
	}

	$status = true;

	$now = time();
	$cutoffdate = $now - ($CFG->forum_oldpostdays * 24 * 3600);

	if (empty($postids)) {
		return true;

	} else if (count($postids) > 200) {
		while ($part = array_splice($postids, 0, 200)) {
			$status = forum_tp_mark_posts_read($user, $part) && $status;
		}
		return $status;
	}

	$sql = "SELECT id
			  FROM {$CFG->prefix}forum_read
			 WHERE userid = $user->id AND postid IN (".implode(',', $postids).")";
	if ($existing = get_records_sql($sql)) {
		$existing = array_keys($existing);
	} else {
		$existing = array();
	}

	$new = array_diff($postids, $existing);

	if ($new) {
		$sql = "INSERT INTO {$CFG->prefix}forum_read (userid, postid, discussionid, forumid, firstread, lastread)

				SELECT $user->id, p.id, p.discussion, d.forum, $now, $now
				  FROM {$CFG->prefix}forum_posts p
					   JOIN {$CFG->prefix}forum_discussions d	   ON d.id = p.discussion
					   JOIN {$CFG->prefix}forum f				   ON f.id = d.forum
					   LEFT JOIN {$CFG->prefix}forum_track_prefs tf ON (tf.userid = $user->id AND tf.forumid = f.id)
				 WHERE p.id IN (".implode(',', $new).")
					   AND p.modified >= $cutoffdate
					   AND (f.trackingtype = ".FORUM_TRACKING_ON."
							OR (f.trackingtype = ".FORUM_TRACKING_OPTIONAL." AND tf.id IS NULL))";
		$status = execute_sql($sql, false) && $status;
	}

	if ($existing) {
		$sql = "UPDATE {$CFG->prefix}forum_read
				   SET lastread = $now
				 WHERE userid = $user->id AND postid IN (".implode(',', $existing).")";
		$status = execute_sql($sql, false) && $status;
	}

	return $status;
}

/**
 * Mark post as read.
 */
function forum_tp_add_read_record($userid, $postid) {
	global $CFG;

	$now = time();
	$cutoffdate = $now - ($CFG->forum_oldpostdays * 24 * 3600);

	if (!record_exists('forum_read', 'userid', $userid, 'postid', $postid)) {
		$sql = "INSERT INTO {$CFG->prefix}forum_read (userid, postid, discussionid, forumid, firstread, lastread)

				SELECT $userid, p.id, p.discussion, d.forum, $now, $now
				  FROM {$CFG->prefix}forum_posts p
					   JOIN {$CFG->prefix}forum_discussions d ON d.id = p.discussion
				 WHERE p.id = $postid AND p.modified >= $cutoffdate";
		return execute_sql($sql, false);

	} else {
		$sql = "UPDATE {$CFG->prefix}forum_read
				   SET lastread = $now
				 WHERE userid = $userid AND postid = $userid";
		return execute_sql($sql, false);
	}
}

/**
 * Returns all records in the 'forum_read' table matching the passed keys, indexed
 * by userid.
 */
function forum_tp_get_read_records($userid=-1, $postid=-1, $discussionid=-1, $forumid=-1) {
	$select = '';
	if ($userid > -1) {
		if ($select != '') $select .= ' AND ';
		$select .= 'userid = \''.$userid.'\'';
	}
	if ($postid > -1) {
		if ($select != '') $select .= ' AND ';
		$select .= 'postid = \''.$postid.'\'';
	}
	if ($discussionid > -1) {
		if ($select != '') $select .= ' AND ';
		$select .= 'discussionid = \''.$discussionid.'\'';
	}
	if ($forumid > -1) {
		if ($select != '') $select .= ' AND ';
		$select .= 'forumid = \''.$forumid.'\'';
	}

	return get_records_select('forum_read', $select);
}

/**
 * Returns all read records for the provided user and discussion, indexed by postid.
 */
function forum_tp_get_discussion_read_records($userid, $discussionid) {
	$select = 'userid = \''.$userid.'\' AND discussionid = \''.$discussionid.'\'';
	$fields = 'postid, firstread, lastread';
	return get_records_select('forum_read', $select, '', $fields);
}

/**
 * If its an old post, do nothing. If the record exists, the maintenance will clear it up later.
 */
function forum_tp_mark_post_read($userid, $post, $forumid) {
	if (!forum_tp_is_post_old($post)) {
		return forum_tp_add_read_record($userid, $post->id);
	} else {
		return true;
	}
}

/**
 * Marks a whole forum as read, for a given user
 */
function forum_tp_mark_forum_read($user, $forumid, $groupid=false) {
	global $CFG;

	$cutoffdate = time() - ($CFG->forum_oldpostdays*24*60*60);

	$groupsel = "";
	if ($groupid !== false) {
		$groupsel = " AND (d.groupid = $groupid OR d.groupid = -1)";
	}

	$sql = "SELECT p.id
			  FROM {$CFG->prefix}forum_posts p
				   LEFT JOIN {$CFG->prefix}forum_discussions d ON d.id = p.discussion
				   LEFT JOIN {$CFG->prefix}forum_read r		ON (r.postid = p.id AND r.userid = $user->id)
			 WHERE d.forum = $forumid
				   AND p.modified >= $cutoffdate AND r.id is NULL
				   $groupsel";

	if ($posts = get_records_sql($sql)) {
		$postids = array_keys($posts);
		return forum_tp_mark_posts_read($user, $postids);
	}

	return true;
}

/**
 * Marks a whole discussion as read, for a given user
 */
function forum_tp_mark_discussion_read($user, $discussionid) {
	global $CFG;

	$cutoffdate = time() - ($CFG->forum_oldpostdays*24*60*60);

	$sql = "SELECT p.id
			  FROM {$CFG->prefix}forum_posts p
				   LEFT JOIN {$CFG->prefix}forum_read r ON (r.postid = p.id AND r.userid = $user->id)
			 WHERE p.discussion = $discussionid
				   AND p.modified >= $cutoffdate AND r.id is NULL";

	if ($posts = get_records_sql($sql)) {
		$postids = array_keys($posts);
		return forum_tp_mark_posts_read($user, $postids);
	}

	return true;
}

/**
 *
 */
function forum_tp_is_post_read($userid, $post) {
	return (forum_tp_is_post_old($post) ||
			record_exists('forum_read', 'userid', $userid, 'postid', $post->id));
}

/**
 *
 */
function forum_tp_is_post_old($post, $time=null) {
	global $CFG;

	if (is_null($time)) {
		$time = time();
	}
	return ($post->modified < ($time - ($CFG->forum_oldpostdays * 24 * 3600)));
}

/**
 * Returns the count of records for the provided user and discussion.
 */
function forum_tp_count_discussion_read_records($userid, $discussionid) {
	global $CFG;

	$cutoffdate = isset($CFG->forum_oldpostdays) ? (time() - ($CFG->forum_oldpostdays*24*60*60)) : 0;

	$sql = 'SELECT COUNT(DISTINCT p.id) '.
		   'FROM '.$CFG->prefix.'forum_discussions d '.
		   'LEFT JOIN '.$CFG->prefix.'forum_read r ON d.id = r.discussionid AND r.userid = '.$userid.' '.
		   'LEFT JOIN '.$CFG->prefix.'forum_posts p ON p.discussion = d.id '.
				'AND (p.modified < '.$cutoffdate.' OR p.id = r.postid) '.
		   'WHERE d.id = '.$discussionid;

	return (count_records_sql($sql));
}

/**
 * Returns the count of records for the provided user and discussion.
 */
function forum_tp_count_discussion_unread_posts($userid, $discussionid) {
	global $CFG;

	$cutoffdate = isset($CFG->forum_oldpostdays) ? (time() - ($CFG->forum_oldpostdays*24*60*60)) : 0;

	$sql = 'SELECT COUNT(p.id) '.
		   'FROM '.$CFG->prefix.'forum_posts p '.
		   'LEFT JOIN '.$CFG->prefix.'forum_read r ON r.postid = p.id AND r.userid = '.$userid.' '.
		   'WHERE p.discussion = '.$discussionid.' '.
				'AND p.modified >= '.$cutoffdate.' AND r.id is NULL';

	return (count_records_sql($sql));
}

/**
 * Returns the count of posts for the provided forum and [optionally] group.
 */
function forum_tp_count_forum_posts($forumid, $groupid=false) {
	global $CFG;

	$sql = 'SELECT COUNT(*) '.
		   'FROM '.$CFG->prefix.'forum_posts fp,'.$CFG->prefix.'forum_discussions fd '.
		   'WHERE fd.forum = '.$forumid.' AND fp.discussion = fd.id';
	if ($groupid !== false) {
		$sql .= ' AND (fd.groupid = '.$groupid.' OR fd.groupid = -1)';
	}
	$count = count_records_sql($sql);


	return $count;
}

/**
 * Returns the count of records for the provided user and forum and [optionally] group.
 */
function forum_tp_count_forum_read_records($userid, $forumid, $groupid=false) {
	global $CFG;

	$cutoffdate = time() - ($CFG->forum_oldpostdays*24*60*60);

	$groupsel = '';
	if ($groupid !== false) {
		$groupsel = "AND (d.groupid = $groupid OR d.groupid = -1)";
	}

	$sql = "SELECT COUNT(p.id)
			  FROM  {$CFG->prefix}forum_posts p
					JOIN {$CFG->prefix}forum_discussions d ON d.id = p.discussion
					LEFT JOIN {$CFG->prefix}forum_read r   ON (r.postid = p.id AND r.userid= $userid)
			  WHERE d.forum = $forumid
					AND (p.modified < $cutoffdate OR (p.modified >= $cutoffdate AND r.id IS NOT NULL))
					$groupsel";

	return get_field_sql($sql);
}

/**
 * Returns the count of records for the provided user and course.
 * Please note that group access is ignored!
 */
function forum_tp_get_course_unread_posts($userid, $courseid) {
	global $CFG;

	$now = round(time(), -2); // db cache friendliness
	$cutoffdate = $now - ($CFG->forum_oldpostdays*24*60*60);

	if (!empty($CFG->forum_enabletimedposts)) {
		$timedsql = "AND d.timestart < $now AND (d.timeend = 0 OR d.timeend > $now)";
	} else {
		$timedsql = "";
	}

	$sql = "SELECT f.id, COUNT(p.id) AS unread
			  FROM {$CFG->prefix}forum_posts p
				   JOIN {$CFG->prefix}forum_discussions d	   ON d.id = p.discussion
				   JOIN {$CFG->prefix}forum f				   ON f.id = d.forum
				   JOIN {$CFG->prefix}course c				  ON c.id = f.course
				   LEFT JOIN {$CFG->prefix}forum_read r		 ON (r.postid = p.id AND r.userid = $userid)
				   LEFT JOIN {$CFG->prefix}forum_track_prefs tf ON (tf.userid = $userid AND tf.forumid = f.id)
			 WHERE f.course = $courseid
				   AND p.modified >= $cutoffdate AND r.id is NULL
				   AND (f.trackingtype = ".FORUM_TRACKING_ON."
						OR (f.trackingtype = ".FORUM_TRACKING_OPTIONAL." AND tf.id IS NULL))
				   $timedsql
		  GROUP BY f.id";

	if ($return = get_records_sql($sql)) {
		return $return;
	}

	return array();
}

/**
 * Returns the count of records for the provided user and forum and [optionally] group.
 */
function forum_tp_count_forum_unread_posts($cm, $course) {
	global $CFG, $USER;

	static $readcache = array();

	$forumid = $cm->instance;

	if (!isset($readcache[$course->id])) {
		$readcache[$course->id] = array();
		if ($counts = forum_tp_get_course_unread_posts($USER->id, $course->id)) {
			foreach ($counts as $count) {
				$readcache[$course->id][$count->id] = $count->unread;
			}
		}
	}

	if (empty($readcache[$course->id][$forumid])) {
		// no need to check group mode ;-)
		return 0;
	}

	$groupmode = groups_get_activity_groupmode($cm, $course);

	if ($groupmode != SEPARATEGROUPS) {
		return $readcache[$course->id][$forumid];
	}

	if (has_capability('moodle/site:accessallgroups', get_context_instance(CONTEXT_MODULE, $cm->id))) {
		return $readcache[$course->id][$forumid];
	}

	require_once($CFG->dirroot.'/course/lib.php');

	$modinfo =& get_fast_modinfo($course);
	if (is_null($modinfo->groups)) {
		$modinfo->groups = groups_get_user_groups($course->id, $USER->id);
	}

	if (empty($CFG->enablegroupings)) {
		$mygroups = $modinfo->groups[0];
	} else {
		$mygroups = $modinfo->groups[$cm->groupingid];
	}

	// add all groups posts
	if (empty($mygroups)) {
		$mygroups = array(-1=>-1);
	} else {
		$mygroups[-1] = -1;
	}
	$mygroups = implode(',', $mygroups);


	$now = round(time(), -2); // db cache friendliness
	$cutoffdate = $now - ($CFG->forum_oldpostdays*24*60*60);

	if (!empty($CFG->forum_enabletimedposts)) {
		$timedsql = "AND d.timestart < $now AND (d.timeend = 0 OR d.timeend > $now)";
	} else {
		$timedsql = "";
	}

	$sql = "SELECT COUNT(p.id)
			  FROM {$CFG->prefix}forum_posts p
				   JOIN {$CFG->prefix}forum_discussions d ON p.discussion = d.id
				   LEFT JOIN {$CFG->prefix}forum_read r   ON (r.postid = p.id AND r.userid = $USER->id)
			 WHERE d.forum = $forumid
				   AND p.modified >= $cutoffdate AND r.id is NULL
				   $timedsql
				   AND d.groupid IN ($mygroups)";

	return get_field_sql($sql);
}

/**
 * Deletes read records for the specified index. At least one parameter must be specified.
 */
function forum_tp_delete_read_records($userid=-1, $postid=-1, $discussionid=-1, $forumid=-1) {
	$select = '';
	if ($userid > -1) {
		if ($select != '') $select .= ' AND ';
		$select .= 'userid = \''.$userid.'\'';
	}
	if ($postid > -1) {
		if ($select != '') $select .= ' AND ';
		$select .= 'postid = \''.$postid.'\'';
	}
	if ($discussionid > -1) {
		if ($select != '') $select .= ' AND ';
		$select .= 'discussionid = \''.$discussionid.'\'';
	}
	if ($forumid > -1) {
		if ($select != '') $select .= ' AND ';
		$select .= 'forumid = \''.$forumid.'\'';
	}
	if ($select == '') {
		return false;
	}
	else {
		return delete_records_select('forum_read', $select);
	}
}
/**
 * Get a list of forums not tracked by the user.
 *
 * @param int $userid The id of the user to use.
 * @param int $courseid The id of the course being checked.
 * @return mixed An array indexed by forum id, or false.
 */
function forum_tp_get_untracked_forums($userid, $courseid) {
	global $CFG;

	$sql = "SELECT f.id
			  FROM {$CFG->prefix}forum f
				   LEFT JOIN {$CFG->prefix}forum_track_prefs ft ON (ft.forumid = f.id AND ft.userid = $userid)
			 WHERE f.course = $courseid
				   AND (f.trackingtype = ".FORUM_TRACKING_OFF."
						OR (f.trackingtype = ".FORUM_TRACKING_OPTIONAL." AND ft.id IS NOT NULL))";

	if ($forums = get_records_sql($sql)) {
		foreach ($forums as $forum) {
			$forums[$forum->id] = $forum;
		}
		return $forums;

	} else {
		return array();
	}
}

/**
 * Determine if a user can track forums and optionally a particular forum.
 * Checks the site settings, the user settings and the forum settings (if
 * requested).
 *
 * @param mixed $forum The forum object to test, or the int id (optional).
 * @param mixed $userid The user object to check for (optional).
 * @return boolean
 */
function forum_tp_can_track_forums($forum=false, $user=false) {
	global $USER, $CFG;

	// if possible, avoid expensive
	// queries
	if (empty($CFG->forum_trackreadposts)) {
		return false;
	}

	if ($user === false) {
		$user = $USER;
	}

	if (isguestuser($user) or empty($user->id)) {
		return false;
	}

	if ($forum === false) {
		// general abitily to track forums
		return (bool)$user->trackforums;
	}


	// Work toward always passing an object...
	if (is_numeric($forum)) {
		debugging('Better use proper forum object.', DEBUG_DEVELOPER);
		$forum = get_record('forum', 'id', $forum, '','','','', 'id,trackingtype');
	}

	$forumallows = ($forum->trackingtype == FORUM_TRACKING_OPTIONAL);
	$forumforced = ($forum->trackingtype == FORUM_TRACKING_ON);

	return ($forumforced || $forumallows)  && !empty($user->trackforums);
}

/**
 * Tells whether a specific forum is tracked by the user. A user can optionally
 * be specified. If not specified, the current user is assumed.
 *
 * @param mixed $forum If int, the id of the forum being checked; if object, the forum object
 * @param int $userid The id of the user being checked (optional).
 * @return boolean
 */
function forum_tp_is_tracked($forum, $user=false) {
	global $USER, $CFG;

	if ($user === false) {
		$user = $USER;
	}

	if (isguestuser($user) or empty($user->id)) {
		return false;
	}

	// Work toward always passing an object...
	if (is_numeric($forum)) {
		debugging('Better use proper forum object.', DEBUG_DEVELOPER);
		$forum = get_record('forum', 'id', $forum);
	}

	if (!forum_tp_can_track_forums($forum, $user)) {
		return false;
	}

	$forumallows = ($forum->trackingtype == FORUM_TRACKING_OPTIONAL);
	$forumforced = ($forum->trackingtype == FORUM_TRACKING_ON);

	return $forumforced ||
		   ($forumallows && get_record('forum_track_prefs', 'userid', $user->id, 'forumid', $forum->id) === false);
}

/**
 *
 */
function forum_tp_start_tracking($forumid, $userid=false) {
	global $USER;

	if ($userid === false) {
		$userid = $USER->id;
	}

	return delete_records('forum_track_prefs', 'userid', $userid, 'forumid', $forumid);
}

/**
 *
 */
function forum_tp_stop_tracking($forumid, $userid=false) {
	global $USER;

	if ($userid === false) {
		$userid = $USER->id;
	}

	if (!record_exists('forum_track_prefs', 'userid', $userid, 'forumid', $forumid)) {
		$track_prefs = new object();
		$track_prefs->userid = $userid;
		$track_prefs->forumid = $forumid;
		insert_record('forum_track_prefs', $track_prefs);
	}

	return forum_tp_delete_read_records($userid, -1, -1, $forumid);
}


/**
 * Clean old records from the forum_read table.
 */
function forum_tp_clean_read_records() {
	global $CFG;

	if (!isset($CFG->forum_oldpostdays)) {
		return;
	}
// Look for records older than the cutoffdate that are still in the forum_read table.
	$cutoffdate = time() - ($CFG->forum_oldpostdays*24*60*60);

	//first get the oldest tracking present - we need tis to speedup the next delete query
	$sql = "SELECT MIN(fp.modified) AS first
			  FROM {$CFG->prefix}forum_posts fp
				   JOIN {$CFG->prefix}forum_read fr ON fr.postid=fp.id";
	if (!$first = get_field_sql($sql)) {
		// nothing to delete;
		return;
	}

	// now delete old tracking info
	$sql = "DELETE
			  FROM {$CFG->prefix}forum_read
			 WHERE postid IN (SELECT fp.id
								FROM {$CFG->prefix}forum_posts fp
							   WHERE fp.modified >= $first AND fp.modified < $cutoffdate)";
	execute_sql($sql, false);
}

/**
 * Sets the last post for a given discussion
 **/
function forum_discussion_update_last_post($discussionid) {
	global $CFG, $db;

// Check the given discussion exists
	if (!record_exists('forum_discussions', 'id', $discussionid)) {
		return false;
	}

// Use SQL to find the last post for this discussion
	$sql = 'SELECT id, userid, modified '.
		   'FROM '.$CFG->prefix.'forum_posts '.
		   'WHERE discussion='.$discussionid.' '.
		   'ORDER BY modified DESC ';

// Lets go find the last post
	if (($lastpost = get_record_sql($sql, true))) {
		$discussionobject = new Object;
		$discussionobject->id = $discussionid;
		$discussionobject->usermodified = $lastpost->userid;
		$discussionobject->timemodified = $lastpost->modified;
		if (update_record('forum_discussions', $discussionobject)) {
			return $lastpost->id;
		}
	}

// To get here either we couldn't find a post for the discussion (weird)
// or we couldn't update the discussion record (weird x2)
	return false;
}


/**
 *
 */
function forum_get_view_actions() {
	return array('view discussion','search','forum','forums','subscribers');
}

/**
 *
 */
function forum_get_post_actions() {
	return array('add discussion','add post','delete discussion','delete post','move discussion','prune post','update post');
}

/**
 * this function returns all the separate forum ids, given a courseid
 * @param int $courseid
 * @return array
 */
function forum_get_separate_modules($courseid) {

	global $CFG,$db;
	$forummodule = get_record("modules", "name", "forum");

	$sql = 'SELECT f.id, f.id FROM '.$CFG->prefix.'forum f, '.$CFG->prefix.'course_modules cm WHERE
		   f.id = cm.instance AND cm.module ='.$forummodule->id.' AND cm.visible = 1 AND cm.course = '.$courseid.'
		   AND cm.groupmode ='.SEPARATEGROUPS;

	return get_records_sql($sql);

}

/**
 *
 */
function forum_check_throttling($forum, $cm=null) {
	global $USER, $CFG;

	if (is_numeric($forum)) {
		$forum = get_record('forum','id',$forum);
	}
	if (!is_object($forum)) {
		return false;  // this is broken.
	}

	if (empty($forum->blockafter)) {
		return true;
	}

	if (empty($forum->blockperiod)) {
		return true;
	}

	if (!$cm) {
		if (!$cm = get_coursemodule_from_instance('forum', $forum->id, $forum->course)) {
			error('Course Module ID was incorrect');
		}
	}

	$modcontext = get_context_instance(CONTEXT_MODULE, $cm->id);
	if(!has_capability('mod/forum:throttlingapplies', $modcontext)) {
		return true;
	}

	// get the number of posts in the last period we care about
	$timenow = time();
	$timeafter = $timenow - $forum->blockperiod;

	$numposts = count_records_sql('SELECT COUNT(p.id) FROM '.$CFG->prefix.'forum_posts p'
								  .' JOIN '.$CFG->prefix.'forum_discussions d'
								  .' ON p.discussion = d.id WHERE d.forum = '.$forum->id
								  .' AND p.userid = '.$USER->id.' AND p.created > '.$timeafter);

	$a = new object();
	$a->blockafter = $forum->blockafter;
	$a->numposts = $numposts;
	$a->blockperiod = get_string('secondstotime'.$forum->blockperiod);

	if ($forum->blockafter <= $numposts) {
		print_error('forumblockingtoomanyposts', 'error', $CFG->wwwroot.'/mod/forum/view.php?f='.$forum->id, $a);
	}
	if ($forum->warnafter <= $numposts) {
		notify(get_string('forumblockingalmosttoomanyposts','forum',$a));
	}


}


/**
 * Removes all grades from gradebook
 * @param int $courseid
 * @param string optional type
 */
function forum_reset_gradebook($courseid, $type='') {
	global $CFG;

	$type = $type ? "AND f.type='$type'" : '';

	$sql = "SELECT f.*, cm.idnumber as cmidnumber, f.course as courseid
			  FROM {$CFG->prefix}forum f, {$CFG->prefix}course_modules cm, {$CFG->prefix}modules m
			 WHERE m.name='forum' AND m.id=cm.module AND cm.instance=f.id AND f.course=$courseid $type";

	if ($forums = get_records_sql($sql)) {
		foreach ($forums as $forum) {
			forum_grade_item_update($forum, 'reset');
		}
	}
}

/**
 * This function is used by the reset_course_userdata function in moodlelib.
 * This function will remove all posts from the specified forum
 * and clean up any related data.
 * @param $data the data submitted from the reset course.
 * @return array status array
 */
function forum_reset_userdata($data) {
	global $CFG;
	require_once($CFG->libdir.'/filelib.php');

	$componentstr = get_string('modulenameplural', 'forum');
	$status = array();

	$removeposts = false;
	if (!empty($data->reset_forum_all)) {
		$removeposts = true;
		$typesql	 = "";
		$typesstr	= get_string('resetforumsall', 'forum');
		$types	   = array();

	} else if (!empty($data->reset_forum_types)){
		$removeposts = true;
		$typesql	 = "";
		$types	   = array();
		$forum_types_all = forum_get_forum_types_all();
		foreach ($data->reset_forum_types as $type) {
			if (!array_key_exists($type, $forum_types_all)) {
				continue;
			}
			$typesql .= " AND f.type='$type'";
			$types[] = $forum_types_all[$type];
		}
		$typesstr = get_string('resetforums', 'forum').': '.implode(', ', $types);

	}

	$alldiscussionssql = "SELECT fd.id
							FROM {$CFG->prefix}forum_discussions fd, {$CFG->prefix}forum f
						   WHERE f.course={$data->courseid} AND f.id=fd.forum";

	$allforumssql	  = "SELECT f.id
							FROM {$CFG->prefix}forum f
						   WHERE f.course={$data->courseid}";

	$allpostssql	   = "SELECT fp.id
							FROM {$CFG->prefix}forum_posts fp, {$CFG->prefix}forum_discussions fd, {$CFG->prefix}forum f
						   WHERE f.course={$data->courseid} AND f.id=fd.forum AND fd.id=fp.discussion";

	if ($removeposts) {
		$discussionssql = "$alldiscussionssql $typesql";
		$forumssql	  = "$allforumssql $typesql";
		$postssql	   = "$allpostssql $typesql";

		// first delete all read flags
		delete_records_select('forum_read', "forumid IN ($forumssql)");

		// remove tracking prefs
		delete_records_select('forum_track_prefs', "forumid IN ($forumssql)");

		// remove posts from queue
		delete_records_select('forum_queue', "discussionid IN ($discussionssql)");

		// remove ratings
		delete_records_select('forum_ratings', "post IN ($postssql)");

		// all posts - initial posts must be kept in single simple discussion forums
		delete_records_select('forum_posts', "discussion IN ($discussionssql) AND parent <> 0"); // first all children
		delete_records_select('forum_posts', "discussion IN ($discussionssql AND f.type <> 'single') AND parent = 0"); // now the initial posts for non single simple

		// finally all discussions except single simple forums
		delete_records_select('forum_discussions', "forum IN ($forumssql AND f.type <> 'single')");

		// now get rid of all attachments
		if ($forums = get_records_sql($forumssql)) {
			foreach ($forums as $forumid=>$unused) {
				fulldelete($CFG->dataroot.'/'.$data->courseid.'/moddata/forum/'.$forumid);
			}
		}

		// remove all grades from gradebook
		if (empty($data->reset_gradebook_grades)) {
			if (empty($types)) {
				forum_reset_gradebook($data->courseid);
			} else {
				foreach ($types as $type) {
					forum_reset_gradebook($data->courseid, $type);
				}
			}
		}

		$status[] = array('component'=>$componentstr, 'item'=>$typesstr, 'error'=>false);
	}

	// remove all ratings
	if (!empty($data->reset_forum_ratings)) {
		delete_records_select('forum_ratings', "post IN ($allpostssql)");
		// remove all grades from gradebook
		if (empty($data->reset_gradebook_grades)) {
			forum_reset_gradebook($data->courseid);
		}
	}

	// remove all subscriptions unconditionally - even for users still enrolled in course
	if (!empty($data->reset_forum_subscriptions)) {
		delete_records_select('forum_subscriptions', "forum IN ($allforumssql)");
		$status[] = array('component'=>$componentstr, 'item'=>get_string('resetsubscriptions','forum'), 'error'=>false);
	}

	// remove all tracking prefs unconditionally - even for users still enrolled in course
	if (!empty($data->reset_forum_track_prefs)) {
		delete_records_select('forum_track_prefs', "forumid IN ($allforumssql)");
		$status[] = array('component'=>$componentstr, 'item'=>get_string('resettrackprefs','forum'), 'error'=>false);
	}

	/// updating dates - shift may be negative too
	if ($data->timeshift) {
		shift_course_mod_dates('forum', array('assesstimestart', 'assesstimefinish'), $data->timeshift, $data->courseid);
		$status[] = array('component'=>$componentstr, 'item'=>get_string('datechanged'), 'error'=>false);
	}

	return $status;
}

/**
 * Called by course/reset.php
 * @param $mform form passed by reference
 */
function forum_reset_course_form_definition(&$mform) {
	$mform->addElement('header', 'forumheader', get_string('modulenameplural', 'forum'));

	$mform->addElement('checkbox', 'reset_forum_all', get_string('resetforumsall','forum'));

	$mform->addElement('select', 'reset_forum_types', get_string('resetforums', 'forum'), forum_get_forum_types_all(), array('multiple' => 'multiple'));
	$mform->setAdvanced('reset_forum_types');
	$mform->disabledIf('reset_forum_types', 'reset_forum_all', 'checked');

	$mform->addElement('checkbox', 'reset_forum_subscriptions', get_string('resetsubscriptions','forum'));
	$mform->setAdvanced('reset_forum_subscriptions');

	$mform->addElement('checkbox', 'reset_forum_track_prefs', get_string('resettrackprefs','forum'));
	$mform->setAdvanced('reset_forum_track_prefs');
	$mform->disabledIf('reset_forum_track_prefs', 'reset_forum_all', 'checked');

	$mform->addElement('checkbox', 'reset_forum_ratings', get_string('deleteallratings'));
	$mform->disabledIf('reset_forum_ratings', 'reset_forum_all', 'checked');
}

/**
 * Course reset form defaults.
 */
function forum_reset_course_form_defaults($course) {
	return array('reset_forum_all'=>1, 'reset_forum_subscriptions'=>0, 'reset_forum_track_prefs'=>0, 'reset_forum_ratings'=>1);
}

/**
 * Converts a forum to use the Roles System
 * @param $forum		- a forum object with the same attributes as a record
 *						from the forum database table
 * @param $forummodid   - the id of the forum module, from the modules table
 * @param $teacherroles - array of roles that have moodle/legacy:teacher
 * @param $studentroles - array of roles that have moodle/legacy:student
 * @param $guestroles   - array of roles that have moodle/legacy:guest
 * @param $cmid		 - the course_module id for this forum instance
 * @return boolean	  - forum was converted or not
 */
function forum_convert_to_roles($forum, $forummodid, $teacherroles=array(),
								$studentroles=array(), $guestroles=array(), $cmid=NULL) {

	global $CFG;

	if (!isset($forum->open) && !isset($forum->assesspublic)) {
		// We assume that this forum has already been converted to use the
		// Roles System. Columns forum.open and forum.assesspublic get dropped
		// once the forum module has been upgraded to use Roles.
		return false;
	}

	if ($forum->type == 'teacher') {

		// Teacher forums should be converted to normal forums that
		// use the Roles System to implement the old behavior.
		// Note:
		//   Seems that teacher forums were never backed up in 1.6 since they
		//   didn't have an entry in the course_modules table.
		require_once($CFG->dirroot.'/course/lib.php');

		if (count_records('forum_discussions', 'forum', $forum->id) == 0) {
			// Delete empty teacher forums.
			delete_records('forum', 'id', $forum->id);
		} else {
			// Create a course module for the forum and assign it to
			// section 0 in the course.
			$mod = new object;
			$mod->course = $forum->course;
			$mod->module = $forummodid;
			$mod->instance = $forum->id;
			$mod->section = 0;
			$mod->visible = 0;	 // Hide the forum
			$mod->visibleold = 0;  // Hide the forum
			$mod->groupmode = 0;

			if (!$cmid = add_course_module($mod)) {
				error('Could not create new course module instance for the teacher forum');
			} else {
				$mod->coursemodule = $cmid;
				if (!$sectionid = add_mod_to_section($mod)) {
					error('Could not add converted teacher forum instance to section 0 in the course');
				} else {
					if (!set_field('course_modules', 'section', $sectionid, 'id', $cmid)) {
						error('Could not update course module with section id');
					}
				}
			}

			// Change the forum type to general.
			$forum->type = 'general';
			if (!update_record('forum', $forum)) {
				error('Could not change forum from type teacher to type general');
			}

			$context = get_context_instance(CONTEXT_MODULE, $cmid);

			// Create overrides for default student and guest roles (prevent).
			foreach ($studentroles as $studentrole) {
				assign_capability('mod/forum:viewdiscussion', CAP_PREVENT, $studentrole->id, $context->id);
				assign_capability('mod/forum:viewhiddentimedposts', CAP_PREVENT, $studentrole->id, $context->id);
				assign_capability('mod/forum:startdiscussion', CAP_PREVENT, $studentrole->id, $context->id);
				assign_capability('mod/forum:replypost', CAP_PREVENT, $studentrole->id, $context->id);
				assign_capability('mod/forum:viewrating', CAP_PREVENT, $studentrole->id, $context->id);
				assign_capability('mod/forum:viewanyrating', CAP_PREVENT, $studentrole->id, $context->id);
				assign_capability('mod/forum:rate', CAP_PREVENT, $studentrole->id, $context->id);
				assign_capability('mod/forum:createattachment', CAP_PREVENT, $studentrole->id, $context->id);
				assign_capability('mod/forum:deleteownpost', CAP_PREVENT, $studentrole->id, $context->id);
				assign_capability('mod/forum:deleteanypost', CAP_PREVENT, $studentrole->id, $context->id);
				assign_capability('mod/forum:splitdiscussions', CAP_PREVENT, $studentrole->id, $context->id);
				assign_capability('mod/forum:movediscussions', CAP_PREVENT, $studentrole->id, $context->id);
				assign_capability('mod/forum:editanypost', CAP_PREVENT, $studentrole->id, $context->id);
				assign_capability('mod/forum:viewqandawithoutposting', CAP_PREVENT, $studentrole->id, $context->id);
				assign_capability('mod/forum:viewsubscribers', CAP_PREVENT, $studentrole->id, $context->id);
				assign_capability('mod/forum:managesubscriptions', CAP_PREVENT, $studentrole->id, $context->id);
				assign_capability('mod/forum:throttlingapplies', CAP_PREVENT, $studentrole->id, $context->id);
			}
			foreach ($guestroles as $guestrole) {
				assign_capability('mod/forum:viewdiscussion', CAP_PREVENT, $guestrole->id, $context->id);
				assign_capability('mod/forum:viewhiddentimedposts', CAP_PREVENT, $guestrole->id, $context->id);
				assign_capability('mod/forum:startdiscussion', CAP_PREVENT, $guestrole->id, $context->id);
				assign_capability('mod/forum:replypost', CAP_PREVENT, $guestrole->id, $context->id);
				assign_capability('mod/forum:viewrating', CAP_PREVENT, $guestrole->id, $context->id);
				assign_capability('mod/forum:viewanyrating', CAP_PREVENT, $guestrole->id, $context->id);
				assign_capability('mod/forum:rate', CAP_PREVENT, $guestrole->id, $context->id);
				assign_capability('mod/forum:createattachment', CAP_PREVENT, $guestrole->id, $context->id);
				assign_capability('mod/forum:deleteownpost', CAP_PREVENT, $guestrole->id, $context->id);
				assign_capability('mod/forum:deleteanypost', CAP_PREVENT, $guestrole->id, $context->id);
				assign_capability('mod/forum:splitdiscussions', CAP_PREVENT, $guestrole->id, $context->id);
				assign_capability('mod/forum:movediscussions', CAP_PREVENT, $guestrole->id, $context->id);
				assign_capability('mod/forum:editanypost', CAP_PREVENT, $guestrole->id, $context->id);
				assign_capability('mod/forum:viewqandawithoutposting', CAP_PREVENT, $guestrole->id, $context->id);
				assign_capability('mod/forum:viewsubscribers', CAP_PREVENT, $guestrole->id, $context->id);
				assign_capability('mod/forum:managesubscriptions', CAP_PREVENT, $guestrole->id, $context->id);
				assign_capability('mod/forum:throttlingapplies', CAP_PREVENT, $guestrole->id, $context->id);
			}
		}
	} else {
		// Non-teacher forum.

		if (empty($cmid)) {
			// We were not given the course_module id. Try to find it.
			if (!$cm = get_coursemodule_from_instance('forum', $forum->id)) {
				notify('Could not get the course module for the forum');
				return false;
			} else {
				$cmid = $cm->id;
			}
		}
		$context = get_context_instance(CONTEXT_MODULE, $cmid);

		// $forum->open defines what students can do:
		//   0 = No discussions, no replies
		//   1 = No discussions, but replies are allowed
		//   2 = Discussions and replies are allowed
		switch ($forum->open) {
			case 0:
				foreach ($studentroles as $studentrole) {
					assign_capability('mod/forum:startdiscussion', CAP_PREVENT, $studentrole->id, $context->id);
					assign_capability('mod/forum:replypost', CAP_PREVENT, $studentrole->id, $context->id);
				}
				break;
			case 1:
				foreach ($studentroles as $studentrole) {
					assign_capability('mod/forum:startdiscussion', CAP_PREVENT, $studentrole->id, $context->id);
					assign_capability('mod/forum:replypost', CAP_ALLOW, $studentrole->id, $context->id);
				}
				break;
			case 2:
				foreach ($studentroles as $studentrole) {
					assign_capability('mod/forum:startdiscussion', CAP_ALLOW, $studentrole->id, $context->id);
					assign_capability('mod/forum:replypost', CAP_ALLOW, $studentrole->id, $context->id);
				}
				break;
		}

		// $forum->assessed defines whether forum rating is turned
		// on (1 or 2) and who can rate posts:
		//   1 = Everyone can rate posts
		//   2 = Only teachers can rate posts
		switch ($forum->assessed) {
			case 1:
				foreach ($studentroles as $studentrole) {
					assign_capability('mod/forum:rate', CAP_ALLOW, $studentrole->id, $context->id);
				}
				foreach ($teacherroles as $teacherrole) {
					assign_capability('mod/forum:rate', CAP_ALLOW, $teacherrole->id, $context->id);
				}
				break;
			case 2:
				foreach ($studentroles as $studentrole) {
					assign_capability('mod/forum:rate', CAP_PREVENT, $studentrole->id, $context->id);
				}
				foreach ($teacherroles as $teacherrole) {
					assign_capability('mod/forum:rate', CAP_ALLOW, $teacherrole->id, $context->id);
				}
				break;
		}

		// $forum->assesspublic defines whether students can see
		// everybody's ratings:
		//   0 = Students can only see their own ratings
		//   1 = Students can see everyone's ratings
		switch ($forum->assesspublic) {
			case 0:
				foreach ($studentroles as $studentrole) {
					assign_capability('mod/forum:viewanyrating', CAP_PREVENT, $studentrole->id, $context->id);
				}
				foreach ($teacherroles as $teacherrole) {
					assign_capability('mod/forum:viewanyrating', CAP_ALLOW, $teacherrole->id, $context->id);
				}
				break;
			case 1:
				foreach ($studentroles as $studentrole) {
					assign_capability('mod/forum:viewanyrating', CAP_ALLOW, $studentrole->id, $context->id);
				}
				foreach ($teacherroles as $teacherrole) {
					assign_capability('mod/forum:viewanyrating', CAP_ALLOW, $teacherrole->id, $context->id);
				}
				break;
		}

		if (empty($cm)) {
			$cm = get_record('course_modules', 'id', $cmid);
		}

		// $cm->groupmode:
		// 0 - No groups
		// 1 - Separate groups
		// 2 - Visible groups
		switch ($cm->groupmode) {
			case 0:
				break;
			case 1:
				foreach ($studentroles as $studentrole) {
					assign_capability('moodle/site:accessallgroups', CAP_PREVENT, $studentrole->id, $context->id);
				}
				foreach ($teacherroles as $teacherrole) {
					assign_capability('moodle/site:accessallgroups', CAP_ALLOW, $teacherrole->id, $context->id);
				}
				break;
			case 2:
				foreach ($studentroles as $studentrole) {
					assign_capability('moodle/site:accessallgroups', CAP_ALLOW, $studentrole->id, $context->id);
				}
				foreach ($teacherroles as $teacherrole) {
					assign_capability('moodle/site:accessallgroups', CAP_ALLOW, $teacherrole->id, $context->id);
				}
				break;
		}
	}
	return true;
}

/**
 * Returns array of forum aggregate types
 */
function forum_get_aggregate_types() {
	return array (FORUM_AGGREGATE_NONE  => get_string('aggregatenone', 'forum'),
				  FORUM_AGGREGATE_AVG   => get_string('aggregateavg', 'forum'),
				  FORUM_AGGREGATE_COUNT => get_string('aggregatecount', 'forum'),
				  FORUM_AGGREGATE_MAX   => get_string('aggregatemax', 'forum'),
				  FORUM_AGGREGATE_MIN   => get_string('aggregatemin', 'forum'),
				  FORUM_AGGREGATE_SUM   => get_string('aggregatesum', 'forum'));
}

/**
 * Returns array of forum layout modes
 */
function forum_get_layout_modes() {
	return array (FORUM_MODE_FLATOLDEST => get_string('modeflatoldestfirst', 'forum'),
				  FORUM_MODE_FLATNEWEST => get_string('modeflatnewestfirst', 'forum'),
				  FORUM_MODE_THREADED   => get_string('modethreaded', 'forum'),
				  FORUM_MODE_NESTED	 => get_string('modenested', 'forum'));
}

/**
 * Returns array of forum types
 */
function forum_get_forum_types() {
	return array ('general'  => get_string('generalforum', 'forum'),
				  'eachuser' => get_string('eachuserforum', 'forum'),
				  'single'   => get_string('singleforum', 'forum'),
				  'qanda'	=> get_string('qandaforum', 'forum'));
}

/**
 * Returns array of all forum layout modes
 */
function forum_get_forum_types_all() {
	return array ('news'	 => get_string('namenews','forum'),
				  'social'   => get_string('namesocial','forum'),
				  'general'  => get_string('generalforum', 'forum'),
				  'eachuser' => get_string('eachuserforum', 'forum'),
				  'single'   => get_string('singleforum', 'forum'),
				  'qanda'	=> get_string('qandaforum', 'forum'));
}

/**
 * Returns array of forum open modes
 */
function forum_get_open_modes() {
	return array ('2' => get_string('openmode2', 'forum'),
				  '1' => get_string('openmode1', 'forum'),
				  '0' => get_string('openmode0', 'forum') );
}

/**
 * Returns all other caps used in module
 */
function forum_get_extra_capabilities() {
	return array('moodle/site:accessallgroups', 'moodle/site:viewfullnames', 'moodle/site:trustcontent');
}

?>
